Guarantees and Contingent Liabilities (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 claim employee	Dec. 31, 2012
Guarantees:
Limitations or indemnifications of reinsurance agreements	$ 0
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	973	1,030
Reinsurance recoverables for asbestos claims	478	496
Reserves for environmental claims	189	193
Reinsurance recoverables for environmental claims	47	48
Percentage of net asbestos and environmental reserves that were for incurred but not reported estimated losses	52.00%	58.00%
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	800
Guarantee on fixed income securities
Guarantees:
Maximum amount at risk pursuant to a guarantee	5
Residual guarantee
Guarantees:
Potential leased automobiles residual value	42
Maximum amount at risk pursuant to a guarantee	$ 0
Guarantee obligations term, low end of range	1 year
Guarantee obligations term, high end of range	3 years