Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Details Textual)

v3.8.0.1
Stockholders' Equity (Details Textual) - 2018 Authorization [Member] - USD ($)
3 Months Ended
May 31, 2018
May 31, 2018
Jan. 31, 2018
Class A and Class B [Member]      
Equity, Class of Treasury Stock [Line Items]      
Repurchase authorization     $ 3,000,000,000.0
Class A Common Stock [Member]      
Equity, Class of Treasury Stock [Line Items]      
Number of shares repurchased 2,730,375 450,508  
Dollar value of shares repurchased $ 591,600,000 $ 100,000,000