Basic and Diluted Net Income (Loss) Per Share (Shares Not Included In Diluted EPS) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock awards | Class A common stock
Antidilutive securities excluded from computation of earnings per share
Anti-dilutive securities excluded from computation of earnings per share	700	400	700
Performance based options (1)
Antidilutive securities excluded from computation of earnings per share
Dilutive securities excluded from computation of earnings per share	3,905	7,247	7,791
Restricted stock units
Antidilutive securities excluded from computation of earnings per share
Dilutive securities excluded from computation of earnings per share	1,382	1,798	1,943
Long-Term Performance Based Plans
Antidilutive securities excluded from computation of earnings per share
Dilutive securities excluded from computation of earnings per share	5,287	9,045	9,734