Equity Equity (Stock Repurchases) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended			78 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 246			$ 246
Treasury Stock, Shares	156,878,891	149,037,831		156,878,891
Acquisition of treasury stock (shares)	8,700,000			154,300,000
Payments for Repurchase of Common Stock	$ 79	$ 482	$ 308
Treasury Stock Acquired, Average Cost Per Share				$ 12.12
Treasury Stock, Value, Acquired, Cost Method				$ 1,900