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Stockholders' Equity (Details Textual) (USD $)
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12 Months Ended | 1 Months Ended | 11 Months Ended | 12 Months Ended | 23 Months Ended | 1 Months Ended | 12 Months Ended | |||||||||||
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Feb. 28, 2013
class_of_stock
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Feb. 29, 2012
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Feb. 28, 2011
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Feb. 28, 2013
Class B Convertible Common Stock [Member]
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Feb. 29, 2012
Class B Convertible Common Stock [Member]
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Nov. 30, 2010
Class A Common Stock [Member]
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May 31, 2010
Class A Common Stock [Member]
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Apr. 30, 2010
Class A Common Stock [Member]
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Feb. 28, 2013
Class A Common Stock [Member]
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Feb. 29, 2012
Class A Common Stock [Member]
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Feb. 28, 2011
Class A Common Stock [Member]
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Feb. 28, 2013
Class A Common Stock [Member]
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Feb. 28, 2013
Class A Common Stock [Member]
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Apr. 30, 2012
ClassA and Class B [Member]
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Apr. 30, 2011
ClassA and Class B [Member]
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Apr. 30, 2010
ClassA and Class B [Member]
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Feb. 28, 2013
Class 1 Common Stock [Member]
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Feb. 29, 2012
Class 1 Common Stock [Member]
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| Class of Stock [Line Items] | ||||||||||||||||||
| Number of classes of common stock with a material number of shares outstanding | 2 | |||||||||||||||||
| Common Stock, conversion features | convertible into shares of Class A Common Stock on a one-to-one basis | convertible into shares of Class A Common Stock on a one-to-one basis | ||||||||||||||||
| Common Stock, voting rights | ten votes per share | one vote per share | generally have no voting rights | |||||||||||||||
| Common stock, dividend rights | 10.00% | |||||||||||||||||
| Common Stock, shares authorized | 30,000,000 | 30,000,000 | 322,000,000 | 322,000,000 | 322,000,000 | 322,000,000 | 25,000,000 | 25,000,000 | ||||||||||
| Common and preferred stock, shares authorized | 378,000,000 | |||||||||||||||||
| Common Stock, shares outstanding | 23,511,235 | 161,265,216 | 161,265,216 | 161,265,216 | 37 | |||||||||||||
| Maximum authorized repurchase of common stock | $ 1,000,000,000.0 | $ 500,000,000 | $ 300,000,000.0 | |||||||||||||||
| Common stock repurchased, shares | 17,994,466 | 21,234,266 | 17,240,101 | 3,421,924 | 2,785,029 | 11,016,451 | 14,023,985 | 21,234,266 | 17,223,404 | 3,970,481 | 25,204,747 | |||||||
| Common stock repurchased | $ 383,000,000 | $ 413,700,000 | $ 300,300,000 | $ 296,700,000 | $ 413,700,000 | $ 300,000,000 | $ 86,300,000 | $ 500,000,000 | ||||||||||
| Average cost of common stock repurchased | $ 21.15 | $ 19.48 | $ 17.42 | $ 21.74 | $ 19.84 | |||||||||||||