v3.3.1.900
Earnings per Share - Antidilutive Securities (Details) - Class A common stock - shares
shares in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Long-term performance based plans      
Dilutive securities excluded from computation of earnings per share      
Dilutive securities excluded from computation of earnings per share (in shares) 0.7 0.7 0.7
Stock awards      
Antidilutive Securities Excluded From Computation Of Earnings Per Share      
Anti-dilutive securities excluded from computation of earnings per share (in shares) 2.3 2.3 2.7