Insurance (Liabilities for Guarantees) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	$ 9,558	$ 8,429	$ 7,500
Incurred guaranteed benefits	1,918	1,206	1,005
Paid guaranteed benefits	(104)	(77)	(76)
Balance at December 31,	11,372	9,558	8,429
Variable Annuity Guarantees: | Guaranteed Minimum Death Benefit
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	1,207	936	685
Incurred guaranteed benefits	440	319	310
Paid guaranteed benefits	(75)	(48)	(59)
Balance at December 31,	1,572	1,207	936
Variable Annuity Guarantees: | Guaranteed Minimum Income Benefit
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	2,529	2,113	1,851
Incurred guaranteed benefits	409	417	262
Paid guaranteed benefits	(1)	(1)	0
Balance at December 31,	2,937	2,529	2,113
Universal and Variable Life Contracts | Secondary Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	5,516	5,092	4,698
Incurred guaranteed benefits	1,044	452	411
Paid guaranteed benefits	(28)	(28)	(17)
Balance at December 31,	6,532	5,516	5,092
Universal and Variable Life Contracts | Secondary Guarantees | Foreign Currency Translation
Movement In Guaranteed Benefit Liability Gross Rollforward
Incurred guaranteed benefits	119	(80)	(343)
Universal and Variable Life Contracts | Paid-Up Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	306	288	266
Incurred guaranteed benefits	25	18	22
Paid guaranteed benefits	0	0	0
Balance at December 31,	331	306	288
Ceded
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	1,513	1,309	1,163
Incurred guaranteed benefits	142	240	158
Paid guaranteed benefits	(51)	(36)	(12)
Balance at December 31,	1,604	1,513	1,309
Ceded | Secondary Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	1,257	1,062	928
Incurred guaranteed benefits	68	195	134
Paid guaranteed benefits	0	0	0
Balance at December 31,	1,325	1,257	1,062
Ceded | Paid-Up Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	215	202	187
Incurred guaranteed benefits	17	13	15
Paid guaranteed benefits	0	0	0
Balance at December 31,	232	215	202
Ceded | Guaranteed Minimum Death Benefit
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	34	38	41
Incurred guaranteed benefits	57	32	9
Paid guaranteed benefits	(51)	(36)	(12)
Balance at December 31,	40	34	38
Ceded | Guaranteed Minimum Income Benefit
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	7	7	7
Incurred guaranteed benefits	0	0	0
Paid guaranteed benefits	0	0	0
Balance at December 31,	7	7	7
Net
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	8,045	7,120	6,337
Incurred guaranteed benefits	1,776	966	847
Paid guaranteed benefits	(53)	(41)	(64)
Balance at December 31,	9,768	8,045	7,120
Net | Secondary Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	4,259	4,030	3,770
Incurred guaranteed benefits	976	257	277
Paid guaranteed benefits	(28)	(28)	(17)
Balance at December 31,	5,207	4,259	4,030
Net | Paid-Up Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	91	86	79
Incurred guaranteed benefits	8	5	7
Paid guaranteed benefits	0	0	0
Balance at December 31,	99	91	86
Net | Guaranteed Minimum Death Benefit
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	1,173	898	644
Incurred guaranteed benefits	383	287	301
Paid guaranteed benefits	(24)	(12)	(47)
Balance at December 31,	1,532	1,173	898
Net | Guaranteed Minimum Income Benefit
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	2,522	2,106	1,844
Incurred guaranteed benefits	409	417	262
Paid guaranteed benefits	(1)	(1)	0
Balance at December 31,	$ 2,930	$ 2,522	$ 2,106