Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Details)

v2.4.1.9
Stockholders' Equity (Details)
 12 Months Ended
Feb. 28, 2015
Feb. 28, 2014
Feb. 28, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Exercise of stock options 2,527,458us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised 6,119,923us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised 8,234,324us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Class A Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Common Stock, end of period 250,839,359us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		248,264,944us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		 
Balance, Treasury Stock, end of period 79,681,859us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		80,225,575us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		 
Class B Convertible Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Common Stock, end of period 28,389,608us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		28,436,565us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		 
Balance, Treasury Stock, end of period 5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		 
Class 1 Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Common Stock, end of period 0us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember 		0us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember 		 
Common Stock [Member] | Class A Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Common Stock, beginning of period 248,264,944us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		242,064,514us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		233,751,797us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Share repurchases     0us-gaap_TreasuryStockSharesAcquired
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Conversion of shares 46,957us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		80,507us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		78,496us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Exercise of stock options 2,527,458us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		6,119,923us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		8,234,221us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Employee stock purchases 0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Grant of restricted stock awards 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Cancellation of restricted shares 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Balance, Common Stock, end of period 250,839,359us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		248,264,944us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		242,064,514us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Common Stock [Member] | Class A Common Stock [Member] | Restricted stock units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Common Stock [Member] | Class A Common Stock [Member] | Performance share units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		 
Common Stock [Member] | Class B Convertible Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Common Stock, beginning of period 28,436,565us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		28,517,035us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		28,583,916us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Share repurchases     0us-gaap_TreasuryStockSharesAcquired
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Conversion of shares (46,957)us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		(80,470)us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		(66,881)us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Exercise of stock options 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Employee stock purchases 0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Grant of restricted stock awards 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Cancellation of restricted shares 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Balance, Common Stock, end of period 28,389,608us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		28,436,565us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		28,517,035us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Common Stock [Member] | Class B Convertible Common Stock [Member] | Restricted stock units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Common Stock [Member] | Class B Convertible Common Stock [Member] | Performance share units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		 
Common Stock [Member] | Class 1 Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Common Stock, beginning of period 0us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		37us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		11,549us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Share repurchases     0us-gaap_TreasuryStockSharesAcquired
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Conversion of shares 0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		(37)us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		(11,615)us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Exercise of stock options 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		103us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Employee stock purchases 0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Grant of restricted stock awards 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Cancellation of restricted shares 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Balance, Common Stock, end of period 0us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		37us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Common Stock [Member] | Class 1 Common Stock [Member] | Restricted stock units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Common Stock [Member] | Class 1 Common Stock [Member] | Performance share units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_ConvertibleCommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		 
Treasury Stock [Member] | Class A Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Treasury Stock, beginning of period 80,225,575us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		80,799,298us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		63,015,441us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Share repurchases     17,994,466us-gaap_TreasuryStockSharesAcquired
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Conversion of shares 0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Exercise of stock options 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Employee stock purchases (117,301)us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(163,817)us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(210,895)us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Grant of restricted stock awards (6,424)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(12,375)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(18,190)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Cancellation of restricted shares 8,426us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		33,661us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		61,140us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Balance, Treasury Stock, end of period 79,681,859us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		80,225,575us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		80,799,298us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Treasury Stock [Member] | Class A Common Stock [Member] | Restricted stock units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units (140,396)us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(121,539)us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(42,664)us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Shares withheld to satisfy tax withholding requirements 101,499us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		96,767us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		23,836us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Treasury Stock [Member] | Class A Common Stock [Member] | Performance share units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units (288,021)us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		(309,653)us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		 
Shares withheld to satisfy tax withholding requirements 248,499us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		267,577us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		 
Treasury Stock [Member] | Class B Convertible Common Stock [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Balance, Treasury Stock, beginning of period 5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Share repurchases     0us-gaap_TreasuryStockSharesAcquired
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Conversion of shares 0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Exercise of stock options 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Employee stock purchases 0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Grant of restricted stock awards 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Cancellation of restricted shares 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Balance, Treasury Stock, end of period 5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		5,005,800us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Treasury Stock [Member] | Class B Convertible Common Stock [Member] | Restricted stock units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
Treasury Stock [Member] | Class B Convertible Common Stock [Member] | Performance share units [Member]      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Vesting of stock units 0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember 		0us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember