Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance (in shares) at Dec. 31, 2012		137,100				(30,000)
Balance at Dec. 31, 2012	$ 757	$ 1	$ 8,211	$ (2,376)	$ 110	$ (5,189)
Comprehensive income (loss):
Net income	16			16
Other comprehensive income (loss)	7				7
Total comprehensive income (loss)	23
Net activity related to restricted stock units (in shares)						400
Net activity related to restricted stock units	10		(197)			$ 207
Number of Options - Exercised						900
Exercise of stock options	2		(155)			$ 157
Excess Tax Benefit from Share-based Compensation, Financing Activities	3		3
Activity related to employee stock purchase plan	1		(1)			$ 2
Repurchase of warrants	(78)		(78)
Sale of call options, net of tax of $(1)	103		110
Treasury Stock, Shares						200
Treasury Stock, Value						$ (7)
Balance (in shares) at Dec. 31, 2013		137,100				(30,500)
Balance at Dec. 31, 2013	771	$ 1	7,893	(2,360)	117	$ (4,880)
Comprehensive income (loss):
Stock Repurchased During Period, Shares						(1,600)
Repurchases of common stock	(48)					$ (50)
Stock Repurchased During Period, Value	(50)
Balance (in shares) at Dec. 31, 2012		137,100				(30,000)
Balance at Dec. 31, 2012	757	$ 1	8,211	(2,376)	110	$ (5,189)
Balance (in shares) at Dec. 31, 2015		137,100				(39,300)
Balance at Dec. 31, 2015	439	$ 1	7,010	(1,802)	(147)	$ (4,623)
Comprehensive income (loss):
Stock Repurchased During Period, Value	(745)
Balance (in shares) at Dec. 31, 2013		137,100				(30,500)
Balance at Dec. 31, 2013	771	$ 1	7,893	(2,360)	117	$ (4,880)
Comprehensive income (loss):
Net income	245			245
Other comprehensive income (loss)	(139)				(139)
Total comprehensive income (loss)	106
Net activity related to restricted stock units (in shares)						700
Net activity related to restricted stock units	10		(143)			$ 153
Number of Options - Exercised						100
Exercise of stock options	0		(20)			$ 20
Excess Tax Benefit from Share-based Compensation, Financing Activities	12		12
Activity related to employee stock purchase plan	$ 0		(1)			$ 1
Stock Issued During Period, Shares, Conversion of Convertible Securities	(4,000)					(4,000)
Stock Issued During Period, Value, Conversion of Convertible Securities	$ 66		(529)			$ 595
Balance (in shares) at Dec. 31, 2014		137,100				(31,400)
Balance at Dec. 31, 2014	665	$ 1	7,212	(2,115)	(22)	$ (4,411)
Comprehensive income (loss):
Stock Repurchased During Period, Shares						(5,700)
Repurchases of common stock	(297)					$ (300)
Stock Repurchased During Period, Value	(300)
Net income	313
Other comprehensive income (loss)	(125)				(125)
Total comprehensive income (loss)	188
Net activity related to restricted stock units (in shares)						900
Net activity related to restricted stock units	$ (13)		(191)			$ 178
Number of Options - Exercised	20					0
Exercise of stock options	$ 0		(3)			$ 3
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(7)		(7)
Activity related to employee stock purchase plan	0		(1)			$ 1
Balance (in shares) at Dec. 31, 2015		137,100				(39,300)
Balance at Dec. 31, 2015	$ 439	$ 1	$ 7,010	$ (1,802)	$ (147)	$ (4,623)
Comprehensive income (loss):
Stock Repurchased During Period, Shares	(16,100)					(8,800)
Repurchases of common stock	$ (393)					$ (394)
Stock Repurchased During Period, Value	$ (394)