Equity and Equity Compensation - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Capital stock shares authorized	2,000,000,000.0
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	500,000,000
Treasury stock acquired, weighted average cost per share	$ 17.70	$ 15.82
Share-based compensation arrangement by share-based payment award, number of shares authorized	157,000,000
Common Stock, capital shares reserved for future issuance	27,000,000
Share-based compensation	$ 76,000,000	$ 81,000,000	$ 90,000,000
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized	$ 61,000,000
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, shares	2,500,000
Share-based compensation arrangement by share-based payment award, options, outstanding, shares	5,300,000
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average exercise price	$ 15.05
Share-based compensation arrangement by share-based payment award, options, exercisable, shares	4,600,000
Employee service share-based compensation, tax benefit from compensation expense	$ 0	$ 0	$ 0