Derivative Financial Instruments and Off-balance sheet Financial Instruments (Details 2) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Asset derivatives
Asset derivatives gross amount	$ 57	$ 92
Asset derivatives, Gross liability	(1)	0
Total asset derivatives, Fair value, net	56	92
Liability derivatives
Liability derivatives gross amount	(313)	(356)
Liability derivatives, Gross asset	5	2
Derivative liabilities net amount on balance sheet	(308)	(354)
OTC derivatives
Asset derivatives
Asset derivatives gross amount	15	7
Asset derivatives, Gross liability	(6)	(2)
Derivative asset offsets under cash collateral received	(5)	0
Total asset derivatives, Fair value, net	4	5
Derivative assets pledged under securities collateral	(1)	(4)
Derivative Asset, Fair Value, Amount Offset Against Collateral	3	1
Liability derivatives
Liability derivatives gross amount	(9)	(11)
Liability derivatives, Gross asset	6	2
Derivative liability offsets under cash collateral pledged	(5)	0
Derivative liabilities net amount on balance sheet	(8)	(9)
Derivative liabilities received under securities collateral	7	7
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ (1)	$ (2)