Guarantees and Contingent Liabilities (Details) (USD $)	6 Months Ended
	Jun. 30, 2012 claim employee	Dec. 31, 2011
Proceedings:
Number of former employee agents plaintiffs seek benefits for	6,500
Number of claims asserted in Romero II	3
Number of claims barred in Romero II	2
Reserves for asbestos claims	$ 1,030,000,000	$ 1,080,000,000
Reinsurance recoverables for asbestos claims	500,000,000	529,000,000
Reserves for environmental claims	181,000,000	185,000,000
Reinsurance recoverables for environmental claims	38,000,000	40,000,000
Percentage of net asbestos and environmental reserves that were for incurred but not reported estimated losses	58.00%	59.00%
Minimum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued	0
Maximum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued	855,000,000
Guarantee on fixed income securities
Guarantees:
Maximum amount at risk pursuant to a guarantee	28,000,000
Residual guarantee
Guarantees:
Maximum amount at risk pursuant to a guarantee	$ 27,000,000
Guarantee obligations term, low end of range	1 year
Guarantee obligations term, high end of range	3 years