Insurance (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	$ 5,998	$ 5,084	$ 1,248
Acquisitions			3,108
Incurred guaranteed benefits	1,396	1,061	820
Paid guaranteed benefits	(161)	(147)	(92)
Balance at December 31,	7,233	5,998	5,084
Ceded [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	831	771	310
Acquisitions			30
Incurred guaranteed benefits	180	80	446
Paid guaranteed benefits	(20)	(20)	(15)
Balance at December 31,	991	831	771
Net [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	5,167	4,313	938
Acquisitions			3,078
Incurred guaranteed benefits	1,216	981	374
Paid guaranteed benefits	(141)	(127)	(77)
Balance at December 31,	6,242	5,167	4,313
Variable Annuity Guarantees [Member] | Guaranteed Minimum Death Benefits [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	432	272	168
Acquisitions			46
Incurred guaranteed benefits	252	273	149
Paid guaranteed benefits	(117)	(113)	(91)
Balance at December 31,	567	432	272
Variable Annuity Guarantees [Member] | Guaranteed Minimum Income Benefits [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	882	623	402
Acquisitions			110
Incurred guaranteed benefits	771	269	111
Paid guaranteed benefits	(18)	(10)	0
Balance at December 31,	1,635	882	623
Variable Annuity Guarantees [Member] | Ceded [Member] | Guaranteed Minimum Death Benefits [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	54	39	6
Acquisitions			30
Incurred guaranteed benefits	22	35	18
Paid guaranteed benefits	(20)	(20)	(15)
Balance at December 31,	56	54	39
Variable Annuity Guarantees [Member] | Ceded [Member] | Guaranteed Minimum Income Benefits [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	8	(1)	0
Acquisitions			0
Incurred guaranteed benefits	1	9	(1)
Paid guaranteed benefits	0	0	0
Balance at December 31,	9	8	(1)
Variable Annuity Guarantees [Member] | Net [Member] | Guaranteed Minimum Death Benefits [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	378	233	162
Acquisitions			16
Incurred guaranteed benefits	230	238	131
Paid guaranteed benefits	(97)	(93)	(76)
Balance at December 31,	511	378	233
Variable Annuity Guarantees [Member] | Net [Member] | Guaranteed Minimum Income Benefits [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	874	624	402
Acquisitions			110
Incurred guaranteed benefits	770	260	112
Paid guaranteed benefits	(18)	(10)	0
Balance at December 31,	1,626	874	624
Universal and Variable Life Contracts [Member] | Secondary Guarantees [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	4,463	3,991	504
Acquisitions			2,952
Incurred guaranteed benefits	348	496	536
Paid guaranteed benefits	(26)	(24)	(1)
Balance at December 31,	4,785	4,463	3,991
Universal and Variable Life Contracts [Member] | Paid-Up Guarantees [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	221	198	174
Acquisitions			0
Incurred guaranteed benefits	25	23	24
Paid guaranteed benefits	0	0	0
Balance at December 31,	246	221	198
Universal and Variable Life Contracts [Member] | Ceded [Member] | Secondary Guarantees [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	614	594	182
Acquisitions			0
Incurred guaranteed benefits	139	20	412
Paid guaranteed benefits	0	0	0
Balance at December 31,	753	614	594
Universal and Variable Life Contracts [Member] | Ceded [Member] | Paid-Up Guarantees [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	155	139	122
Acquisitions			0
Incurred guaranteed benefits	18	16	17
Paid guaranteed benefits	0	0	0
Balance at December 31,	173	155	139
Universal and Variable Life Contracts [Member] | Net [Member] | Secondary Guarantees [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	3,849	3,397	322
Acquisitions			2,952
Incurred guaranteed benefits	209	476	124
Paid guaranteed benefits	(26)	(24)	(1)
Balance at December 31,	4,032	3,849	3,397
Universal and Variable Life Contracts [Member] | Net [Member] | Paid-Up Guarantees [Member]
Movement In Guaranteed Benefit Liability Gross Rollforward
Balance at January 1,	66	59	52
Acquisitions			0
Incurred guaranteed benefits	7	7	7
Paid guaranteed benefits	0	0	0
Balance at December 31,	$ 73	$ 66	$ 59