Closed Block (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Closed Block Liabilities
Future policy benefits	$ 42,586	$ 43,169
Other policy-related balances	298	358
Policyholder dividends payable	466	514
Policyholder dividend obligation	3,828	2,919
Other liabilities	602	613
Total closed block liabilities	47,780	47,573
Assets Designated to the Closed Block
Fixed maturity securities available-for-sale, at estimated fair value	30,546	30,407
Equity securities available-for-sale, at estimated fair value	41	35
Mortgage loans	6,192	6,206
Policy loans	4,670	4,657
Real estate and real estate joint ventures	459	364
Other invested assets	953	857
Total investments	42,861	42,526
Cash and cash equivalents	381	249
Accrued investment income	481	509
Premiums, reinsurance and other receivables	107	109
Current income tax recoverable	2	53
Deferred income tax assets	319	362
Total assets designated to the closed block	44,151	43,808
Excess of closed block liabilities over assets designated to the closed block	3,629	3,765
Amounts included in accumulated other comprehensive income (loss):
Unrealized investment gains (losses), net of income tax	2,891	2,394
Unrealized gains (losses) on derivatives, net of income tax	9	11
Allocated to policyholder dividend obligation, net of income tax	(2,488)	(1,897)
Total amounts included in accumulated other comprehensive income (loss)	412	508
Maximum future earnings to be recognized from closed block assets and liabilities	$ 4,041	$ 4,273