Derivative Financial Instruments (Details 2) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Asset derivatives
Asset derivatives gross amount	$ 69	$ 94
Asset derivatives, Gross liability	(4)	(16)
Derivative assets net amount on balance sheet	65	78
Liability derivatives
Liability derivatives gross amount	(335)	(367)
Liability derivatives, Gross asset	8	6
Derivative liabilities net amount on balance sheet	(327)	(361)
OTC derivatives
Asset derivatives
Asset derivatives gross amount	19	12
Asset derivatives, Gross liability	(12)	(22)
Derivative asset offsets under cash collateral received	(4)	17
Derivative assets net amount on balance sheet	3	7
Derivative assets pledged under securities collateral	0	(4)
Derivative Asset, Fair Value, Amount Offset Against Collateral	3	3
Liability derivatives
Liability derivatives gross amount	(16)	(35)
Liability derivatives, Gross asset	12	22
Derivative liability offsets under cash collateral pledged	(7)	0
Derivative liabilities net amount on balance sheet	(11)	(13)
Derivative liabilities received under securities collateral	8	8
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ (3)	$ (5)