CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Millions	Total	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Treasury Stock [Member]	Accumulated other comprehensive loss [Member]	Class A Common Stock [Member] Common Stock [Member]	Class B Common Stock [Member] Common Stock [Member]
Balance at Dec. 31, 2012	$ 149	$ 1,616	$ (1,392)	$ 0	$ (75)	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(169)	0	(169)	0	0	0	0
Net impact of interest rate derivative instruments, net of tax	34	0	0	0	34	0	0
Stock compensation expense, net	48	48	0	0	0	0	0
Exercise of options and warrants	104	104	0	0	0	0	0
Purchase of treasury stock	(15)	0	0	(15)	0	0	0
Retirement of treasury stock	0	(8)	(7)	15	0	0	0
Balance at Dec. 31, 2013	151	1,760	(1,568)	0	(41)	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(183)	0	(183)	0	0	0	0
Net impact of interest rate derivative instruments, net of tax	19	0	0	0	19	0	0
Stock compensation expense, net	55	55	0	0	0	0	0
Exercise of options and warrants	123	123	0	0	0	0	0
Purchase of treasury stock	(19)	0	0	(19)	0	0	0
Retirement of treasury stock	0	(8)	(11)	19	0	0	0
Balance at Dec. 31, 2014	146	1,930	(1,762)	0	(22)	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(271)	0	(271)	0	0	0	0
Net impact of interest rate derivative instruments, net of tax	9	0	0	0	9	0	0
Stock compensation expense, net	78	78	0	0	0	0	0
Exercise of options and warrants	30	30	0	0	0	0	0
Purchase of treasury stock	(38)	0	0	(38)	0	0	0
Retirement of treasury stock	0	(10)	(28)	38	0	0	0
Balance at Dec. 31, 2015	$ (46)	$ 2,028	$ (2,061)	$ 0	$ (13)	$ 0	$ 0