Basic and Diluted Net Income (Loss) Per Share (Details 2) - Class A common stock - shares shares in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Stock awards
Antidilutive securities excluded from computation of earnings per share
Anti-dilutive securities excluded from computation of earnings per share	600	300
Performance based options (1)
Antidilutive securities excluded from computation of earnings per share
Dilutive securities excluded from computation of earnings per share	3,949	7,339
Restricted performance units (1)
Antidilutive securities excluded from computation of earnings per share
Dilutive securities excluded from computation of earnings per share	1,389	1,834
Long-Term Performance Based Plans
Antidilutive securities excluded from computation of earnings per share
Dilutive securities excluded from computation of earnings per share	5,338	9,173