Equity Stock Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		69 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased During Period, Shares	8.7		154.3
Stock Repurchased During Period, Value	$ 79	$ 35	$ 1,900
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 264		$ 264
Treasury Stock Acquired, Average Cost Per Share			$ 12.12