Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Summary of deferred policy acquisition costs
Amortization of deferred policy acquisition costs	$ 846	$ 901
Property and Casualty Insurance [Member]
Summary of deferred policy acquisition costs
Policy acquisition costs	198	189
Annuity and Supplemental Insurance [Member]
Summary of deferred policy acquisition costs
Policy acquisition costs	955	898
Policyholder sales inducements	200	207
Present value of future profits ("PVFP")	135	144
Impact of unrealized gains and losses on securities	(642)	(537)
Amortization of deferred policy acquisition costs	$ 648	$ 712