Equity Level 4 (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 21, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Class of Warrant or Right [Line Items]
Stock Repurchase Program, Authorized Amount		$ 4,375		$ 4,375
Treasury stock acquired		6.5		18.6
Payments for Repurchase of Common Stock		$ 300		$ 800	$ 1,496
Warrants outstanding		4.5		4.5		7.2
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 9.297		$ 9.297		$ 9.388
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		1,800.0		1,800.0
Stock Repurchase Program, Increase in Number of Shares Authorized to be Repurchased				$ 1,600
Warrant [Member]
Class of Warrant or Right [Line Items]
Warrants Exercised		1.1	3.2	2.7	24.1
Treasury Stock [Member]
Class of Warrant or Right [Line Items]
Treasury Stock, Value, Acquired, Cost Method				$ 800	$ 971
Common Stock [Member]
Class of Warrant or Right [Line Items]
Treasury stock acquired				18,625.0	39,066.0
Subsequent Event [Member]
Class of Warrant or Right [Line Items]
Treasury Stock, Value, Acquired, Cost Method	$ 82
Treasury stock acquired	1.8