Insurance (Liabilities for Guarantees) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	$ 1,029	$ 849	$ 561
Incurred guaranteed benefits	251	185	294
Paid guaranteed benefits	(3)	(5)	(6)
Balance at December 31,	1,277	1,029	849
Ceded
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	609	508	367
Incurred guaranteed benefits	(183)	106	147
Paid guaranteed benefits	(3)	(5)	(6)
Balance at December 31,	423	609	508
Net
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	420	341	194
Incurred guaranteed benefits	434	79	147
Paid guaranteed benefits	0	0	0
Balance at December 31,	854	420	341
Variable Annuity [Member] | Guaranteed Minimum Death Benefit [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	148	109	84
Incurred guaranteed benefits	51	44	31
Paid guaranteed benefits	(3)	(5)	(6)
Balance at December 31,	196	148	109
Variable Annuity [Member] | Guaranteed Minimum Income Benefit [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	390	332	158
Incurred guaranteed benefits	68	58	174
Paid guaranteed benefits	0	0	0
Balance at December 31,	458	390	332
Variable Annuity [Member] | Ceded | Guaranteed Minimum Death Benefit [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	120	86	62
Incurred guaranteed benefits	(80)	39	30
Paid guaranteed benefits	(3)	(5)	(6)
Balance at December 31,	37	120	86
Variable Annuity [Member] | Ceded | Guaranteed Minimum Income Benefit [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	124	110	52
Incurred guaranteed benefits	(100)	14	58
Paid guaranteed benefits	0	0	0
Balance at December 31,	24	124	110
Variable Annuity [Member] | Net | Guaranteed Minimum Death Benefit [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	28	23	22
Incurred guaranteed benefits	131	5	1
Paid guaranteed benefits	0	0	0
Balance at December 31,	159	28	23
Variable Annuity [Member] | Net | Guaranteed Minimum Income Benefit [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	266	222	106
Incurred guaranteed benefits	168	44	116
Paid guaranteed benefits	0	0	0
Balance at December 31,	434	266	222
Universal and Variable Life Contracts | Secondary Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	417	340	261
Incurred guaranteed benefits	124	77	79
Paid guaranteed benefits	0	0	0
Balance at December 31,	541	417	340
Universal and Variable Life Contracts | Paid-Up Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	74	68	58
Incurred guaranteed benefits	8	6	10
Paid guaranteed benefits	0	0	0
Balance at December 31,	82	74	68
Universal and Variable Life Contracts | Ceded | Secondary Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	314	265	212
Incurred guaranteed benefits	(9)	49	53
Paid guaranteed benefits	0	0	0
Balance at December 31,	305	314	265
Universal and Variable Life Contracts | Ceded | Paid-Up Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	51	47	41
Incurred guaranteed benefits	6	4	6
Paid guaranteed benefits	0	0	0
Balance at December 31,	57	51	47
Universal and Variable Life Contracts | Net | Secondary Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	103	75	49
Incurred guaranteed benefits	133	28	26
Paid guaranteed benefits	0	0	0
Balance at December 31,	236	103	75
Universal and Variable Life Contracts | Net | Paid-Up Guarantees
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	23	21	17
Incurred guaranteed benefits	2	2	4
Paid guaranteed benefits	0	0	0
Balance at December 31,	$ 25	$ 23	$ 21