Consolidated Statement of Shareholders' Equity - 9 months ended Sep. 30, 2015 - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Deferred Equity Compensation [Member]
Beginning balance (in shares) at Dec. 31, 2014		158,306,661
Beginning balance at Dec. 31, 2014	$ 5,758	$ 2	$ 1,887	$ 3,494	$ 370	$ 5
Increase (Decrease) in Shareholders' Equity
Net Income	627			627
Dividends ($0.36 per share)	(55)			(55)
Common stock repurchases (in shares)		(15,959,782)
Common stock repurchases	(420)	$ (1)	(419)
Share-based compensation and other (in shares)		572,520
Share-based compensation and other	6		6
Other comprehensive loss	(97)				(97)
Ending balance (in shares) at Sep. 30, 2015		142,919,399
Ending balance at Sep. 30, 2015	$ 5,819	$ 1	$ 1,474	$ 4,066	$ 273	$ 5