Derivative Financial Instruments (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Asset derivatives
Asset derivatives gross amount	$ 177	$ 279
Derivative assets net amount on balance sheet	165	267
Liability derivatives
Liability derivatives gross amount	(694)	(761)
Derivative liabilities net amount on balance sheet	(681)	(746)
OTC derivatives
Asset derivatives
Asset derivatives gross amount	22	28
Offsets of derivative assets under counterparty netting	(13)	(15)
Derivative asset offsets under cash collateral received	(6)	(9)
Derivative assets net amount on balance sheet	3	4
Derivative assets pledged under securities collateral	(2)	(4)
Derivative assets net amount	1
Liability derivatives
Liability derivatives gross amount	(41)	(41)
Offsets of derivative liabilities under counterparty netting	13	15
Derivative liability offsets under cash collateral pledged	(6)	(4)
Derivative liabilities net amount on balance sheet	(34)	(30)
Derivative liabilities received under securities collateral	24	23
Derivative liabilities net amount	$ (10)	$ (7)