Equity Reclassification AOCI (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	$ 9		$ 64
Investment gains, net	118		116
Salaries and employee benefits	317		306
Total	(5)
Available-for-Sale Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total	1	[1]
Available-for-Sale Securities [Member] | Gross [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	(9)
Investment gains, net	8
Salaries and employee benefits	0
Total	(1)
Available-for-Sale Securities [Member] | Tax [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	3
Investment gains, net	(3)
Salaries and employee benefits	0
Total	0
Available-for-Sale Securities [Member] | Net [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	(6)
Investment gains, net	5
Salaries and employee benefits	0
Total	(1)
Other [Member] | Gross [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	0
Investment gains, net	0
Salaries and employee benefits	10
Total	10
Other [Member] | Tax [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	0
Investment gains, net	0
Salaries and employee benefits	(4)
Total	(4)
Other [Member] | Net [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net other-than-temporary impairments	0
Investment gains, net	0
Salaries and employee benefits	6
Total	$ 6

[1] The amounts reclassified from AOCI represent the gain or loss recognized in earnings due to a sale of an available-for-sale security or the recognition of a net impairment recognized in earnings.