Derivative Financial Instruments and Off-balance sheet Financial Instruments (Details 5) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013 party	Dec. 31, 2012 party
Derivative Financial Instruments and Off-balance sheet Financial Instruments
Cash and securities pledged as collateral by counterparties	$ 8
Securities pledged as collateral to counterparties	23
Collateral posted under MNAs, credit-risk-contingent provisions in a liability position	14	25
Collateral posted under MNAs for contracts without credit-risk-contingent liabilities	9
Credit Derivatives
Number of counter-parties	8	7
Notional amount	1,648	6,199
Credit exposure	5	24
Exposure, net of collateral	1	1
Gross liability fair value of contracts containing credit-risk-contingent features	25	62
Gross asset fair value of contracts containing credit-risk-contingent features and subject to MNAs	(9)	(28)
Collateral posted under MNAs for contracts containing credit-risk-contingent features	(14)	(25)
Maximum amount of additional exposure for contracts with credit-risk-contingent features if all features were triggered concurrently	2	9
A+
Credit Derivatives
Number of counter-parties	1	1
Notional amount	22	19
Credit exposure	1
Exposure, net of collateral	1
A
Credit Derivatives
Number of counter-parties	4	3
Notional amount	1,523	2,252
Credit exposure	2	12
A-
Credit Derivatives
Number of counter-parties	1	2
Notional amount	24	311
Credit exposure	1	1
Exposure, net of collateral		1
BBB+
Credit Derivatives
Number of counter-parties	1	1
Notional amount	3	3,617
Credit exposure		11
BBB
Credit Derivatives
Number of counter-parties	1
Notional amount	76
Credit exposure	$ 1