Equity Stock Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended		69 Months Ended
	Jun. 30, 2016	Jun. 30, 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	$ 307	$ 1,900
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 264
Treasury Stock Acquired, Average Cost Per Share			$ 12.12