Consolidated Statements of Shareholders' Equity (unaudited) (USD $) In Millions, unless otherwise specified	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Loss	Treasury Stock at Cost	Retained Earnings
Balance at Beginning of Period at Dec. 31, 2013	$ 9,184	$ 4	$ 3,463	$ (117)	$ (659)	$ 6,493
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	200	0	0	0	0	200
Stock-based Compensation	23	0	23	0	0	0
Exercise of Stock Options	10	0	10	0	0	0
Dividends	(50)	0	0	0	0	(50)
Changes in Treasury Stock, Net	(15)	0	0	0	(15)	0
Tax Benefits Related to Exercise of Stock Options	6	0	6	0	0	0
Net Change in Pension and Other	3	0	0	3	0	0
Balance at End of Period at Mar. 31, 2014	9,361	4	3,502	(114)	(674)	6,643
Balance at Beginning of Period at Dec. 31, 2014	10,325	4	3,624	(90)	(671)	7,458
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	(22)	0	0	0	0	(22)
Stock-based Compensation	21	0	21	0	0	0
Exercise of Stock Options	4	0	4	0	0	0
Dividends	(64)	0	0	0	0	(64)
Changes in Treasury Stock, Net	(12)	0	0	0	(12)	0
Issuance of Shares of Common Stock to Public, Net of Offering Costs	1,112	0	1,112	0	0	0
Net Change in Pension and Other	(7)	0	0	(7)	0	0
Balance at End of Period at Mar. 31, 2015	$ 11,357	$ 4	$ 4,761	$ (97)	$ (683)	$ 7,372