Consolidated Statement of Shareholders' Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Deferred Equity Compensation
Balance at Dec. 31, 2013	$ 5,115	$ 2	$ 2,466	$ 2,482	$ 160	$ 5
Balance (in shares) at Dec. 31, 2013		182,177,866
Increase (Decrease) in Shareholders' Equity
Net income (loss)	556			556
Dividends ($0.33 per share)	(59)			(59)
Common stock repurchases (in shares)		(18,025,594)
Common stock repurchases	(438)		(438)
Share-based compensation and other (in shares)		428,155
Share-based compensation and other	7		7
Other comprehensive income	173				173
Balance at Sep. 30, 2014	5,354	2	2,035	2,979	333	5
Balance (in shares) at Sep. 30, 2014		164,580,427
Balance at Jun. 30, 2014
Increase (Decrease) in Shareholders' Equity
Net income (loss)	355
Other comprehensive income	1				1
Balance at Sep. 30, 2014	$ 5,354				$ 333	$ 5