Closed Block (Liabilities and Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Closed Block Liabilities
Future policy benefits	$ 42,366	$ 42,586
Other policy-related balances	310	298
Policyholder dividends payable	480	466
Policyholder dividend obligation	3,599	3,828
Current income tax payable	14	0
Other liabilities	646	602
Total closed block liabilities	47,415	47,780
Assets Designated to the Closed Block
Fixed maturity securities available-for-sale, at estimated fair value	30,109	30,546
Equity securities available-for-sale, at estimated fair value	91	41
Mortgage loans	6,068	6,192
Policy loans	4,661	4,670
Real estate and real estate joint ventures	460	459
Other invested assets	1,198	953
Total investments	42,587	42,861
Cash and cash equivalents	321	381
Accrued investment income	506	481
Premiums, reinsurance and other receivables	85	107
Current income tax recoverable	0	2
Deferred income tax assets	320	319
Total assets designated to the closed block	43,819	44,151
Excess of closed block liabilities over assets designated to the closed block	3,596	3,629
Amounts included in AOCI:
Unrealized investment gains (losses), net of income tax	2,714	2,891
Unrealized gains (losses) on derivatives, net of income tax	17	9
Allocated to policyholder dividend obligation, net of income tax	(2,339)	(2,488)
Total amounts included in AOCI	392	412
Maximum future earnings to be recognized from closed block assets and liabilities	$ 3,988	$ 4,041