Segment Information (Earnings) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Premiums									$ 21,384	$ 20,475	$ 19,880
Universal life and investment-type product policy fees									2,466	2,363	2,239
Net investment income									11,893	11,785	11,852
Other revenues									1,808	1,699	1,730
Net investment gains (losses)									143	48	(330)
Net derivative gains (losses)									1,037	(1,070)	675
Total revenues	10,585	9,857	9,252	9,037	9,884	8,018	8,632	8,766	38,731	35,300	36,046
Expenses
Policyholder benefits and claims and policyholder dividends									25,095	24,237	23,564
Interest credited to policyholder account balances									2,174	2,253	2,390
Capitalization of DAC									(424)	(562)	(632)
Amortization of DAC and VOBA									695	261	991
Interest expense on debt									151	153	152
Other expenses									5,649	6,136	5,883
Total expenses	9,224	8,017	8,210	7,889	9,106	7,758	7,771	7,843	33,340	32,478	32,348
Provision for income tax expense (benefit)									1,532	681	1,055
Income (loss) from continuing operations, net of income tax	979	1,303	749	828	580	242	646	673	3,859	2,141	2,643
Retail
Expenses
Amortization of DAC and VOBA									652	217	948
Group, Voluntary & Worksite Benefits
Expenses
Amortization of DAC and VOBA									26	25	29
Corporate Benefit Funding
Expenses
Amortization of DAC and VOBA									17	19	12
Corporate & Other
Expenses
Amortization of DAC and VOBA									0	0	2
Operating Segments [Member]
Revenues
Premiums									21,384	20,475	19,880
Universal life and investment-type product policy fees									2,412	2,296	2,189
Net investment income									12,365	12,217	12,137
Other revenues									1,808	1,699	1,730
Net investment gains (losses)									0	0	0
Net derivative gains (losses)									0	0	0
Total revenues									37,969	36,687	35,936
Expenses
Policyholder benefits and claims and policyholder dividends									25,050	24,227	23,425
Interest credited to policyholder account balances									2,163	2,236	2,361
Capitalization of DAC									(424)	(562)	(632)
Amortization of DAC and VOBA									579	491	699
Interest expense on debt									150	150	148
Other expenses									5,655	6,105	5,876
Total expenses									33,173	32,647	31,877
Provision for income tax expense (benefit)									1,322	1,116	1,171
Operating earnings									3,474	2,924	2,888
Operating Segments [Member] | Retail
Revenues
Premiums									4,081	3,992	3,997
Universal life and investment-type product policy fees									1,505	1,397	1,332
Net investment income									5,402	5,385	5,384
Other revenues									430	328	265
Net investment gains (losses)									0	0	0
Net derivative gains (losses)									0	0	0
Total revenues									11,418	11,102	10,978
Expenses
Policyholder benefits and claims and policyholder dividends									6,379	6,246	6,294
Interest credited to policyholder account balances									988	988	1,002
Capitalization of DAC									(376)	(517)	(584)
Amortization of DAC and VOBA									536	447	656
Interest expense on debt									6	5	5
Other expenses									1,797	2,280	2,341
Total expenses									9,330	9,449	9,714
Provision for income tax expense (benefit)									733	579	442
Operating earnings									1,355	1,074	822
Operating Segments [Member] | Group, Voluntary & Worksite Benefits
Revenues
Premiums									14,381	13,732	13,274
Universal life and investment-type product policy fees									716	688	663
Net investment income									1,783	1,790	1,680
Other revenues									415	404	398
Net investment gains (losses)									0	0	0
Net derivative gains (losses)									0	0	0
Total revenues									17,295	16,614	16,015
Expenses
Policyholder benefits and claims and policyholder dividends									13,823	13,191	12,580
Interest credited to policyholder account balances									155	156	167
Capitalization of DAC									(17)	(20)	(24)
Amortization of DAC and VOBA									26	25	29
Interest expense on debt									2	1	1
Other expenses									2,135	1,988	1,901
Total expenses									16,124	15,341	14,654
Provision for income tax expense (benefit)									430	446	477
Operating earnings									741	827	884
Operating Segments [Member] | Corporate Benefit Funding
Revenues
Premiums									2,794	2,675	2,608
Universal life and investment-type product policy fees									191	211	194
Net investment income									4,892	4,611	4,519
Other revenues									287	273	252
Net investment gains (losses)									0	0	0
Net derivative gains (losses)									0	0	0
Total revenues									8,164	7,770	7,573
Expenses
Policyholder benefits and claims and policyholder dividends									4,771	4,723	4,552
Interest credited to policyholder account balances									1,020	1,092	1,192
Capitalization of DAC									(30)	(25)	(24)
Amortization of DAC and VOBA									17	19	12
Interest expense on debt									10	10	9
Other expenses									492	489	438
Total expenses									6,280	6,308	6,179
Provision for income tax expense (benefit)									659	512	488
Operating earnings									1,225	950	906
Operating Segments [Member] | Corporate & Other
Revenues
Premiums									128	76	1
Universal life and investment-type product policy fees									0	0	0
Net investment income									288	431	554
Other revenues									676	694	815
Net investment gains (losses)									0	0	0
Net derivative gains (losses)									0	0	0
Total revenues									1,092	1,201	1,370
Expenses
Policyholder benefits and claims and policyholder dividends									77	67	(1)
Interest credited to policyholder account balances									0	0	0
Capitalization of DAC									(1)	0	0
Amortization of DAC and VOBA									0	0	2
Interest expense on debt									132	134	133
Other expenses									1,231	1,348	1,196
Total expenses									1,439	1,549	1,330
Provision for income tax expense (benefit)									(500)	(421)	(236)
Operating earnings									153	73	276
Significant Reconciling Items [Member]
Revenues
Premiums									0	0	0
Universal life and investment-type product policy fees									54	67	50
Net investment income									(472)	(432)	(285)
Other revenues									0	0	0
Net investment gains (losses)									143	48	(330)
Net derivative gains (losses)									1,037	(1,070)	675
Total revenues									762	(1,387)	110
Expenses
Policyholder benefits and claims and policyholder dividends									45	10	139
Interest credited to policyholder account balances									11	17	29
Capitalization of DAC									0	0	0
Amortization of DAC and VOBA									116	(230)	292
Interest expense on debt									1	3	4
Other expenses									(6)	31	7
Total expenses									167	(169)	471
Provision for income tax expense (benefit)									$ 210	$ (435)	$ (116)