Investments (Fair Values And Gross Unrealized Losses By Credit Rating Category Of Asset Backed Securities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	$ 2,387	$ 6,954
Total, Unrealized Losses	(478)	(804)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	639
Total, Unrealized Losses	(215)
Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	75
Total, Unrealized Losses	(10)
Asset-Backed Securities [Member] | Aa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	101
Total, Unrealized Losses	(13)
Asset-Backed Securities [Member] | A [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	79
Total, Unrealized Losses	(15)
Asset-Backed Securities [Member] | Baa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	90
Total, Unrealized Losses	(19)
Asset-Backed Securities [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	122
Total, Unrealized Losses	(106)
Asset-Backed Securities [Member] | Not Rated [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	172
Total, Unrealized Losses	(52)
ABS CDO [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	40
Total, Unrealized Losses	(62)
ABS CDO [Member] | Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	5
ABS CDO [Member] | Asset-Backed Securities [Member] | Aa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	5
ABS CDO [Member] | Asset-Backed Securities [Member] | A [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	6
Total, Unrealized Losses	(2)
ABS CDO [Member] | Asset-Backed Securities [Member] | Baa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	1
Total, Unrealized Losses	(3)
ABS CDO [Member] | Asset-Backed Securities [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	23
Total, Unrealized Losses	(57)
Corporate CDO [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	233
Total, Unrealized Losses	(79)
Corporate CDO [Member] | Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	45
Total, Unrealized Losses	(8)
Corporate CDO [Member] | Asset-Backed Securities [Member] | Aa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	65
Total, Unrealized Losses	(8)
Corporate CDO [Member] | Asset-Backed Securities [Member] | Baa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	21
Total, Unrealized Losses	(9)
Corporate CDO [Member] | Asset-Backed Securities [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	63
Total, Unrealized Losses	(45)
Corporate CDO [Member] | Asset-Backed Securities [Member] | Not Rated [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	39
Total, Unrealized Losses	(9)
Auto Loans [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	17
Auto Loans [Member] | Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	2
Auto Loans [Member] | Asset-Backed Securities [Member] | Aa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	2
Auto Loans [Member] | Asset-Backed Securities [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	13
Credit Cards [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	3
Credit Cards [Member] | Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	3
Equipment Leases [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	26
Total, Unrealized Losses	(2)
Equipment Leases [Member] | Asset-Backed Securities [Member] | A [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	19
Total, Unrealized Losses	(2)
Equipment Leases [Member] | Asset-Backed Securities [Member] | Baa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	7
Small Business/ Student Loans [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	27
Total, Unrealized Losses	(3)
Small Business/ Student Loans [Member] | Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	16
Total, Unrealized Losses	(2)
Small Business/ Student Loans [Member] | Asset-Backed Securities [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	11
Total, Unrealized Losses	(1)
Other ABS [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	293
Total, Unrealized Losses	(69)
Other ABS [Member] | Asset-Backed Securities [Member] | Aaa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	4
Other ABS [Member] | Asset-Backed Securities [Member] | Aa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	29
Total, Unrealized Losses	(5)
Other ABS [Member] | Asset-Backed Securities [Member] | A [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	54
Total, Unrealized Losses	(11)
Other ABS [Member] | Asset-Backed Securities [Member] | Baa [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	61
Total, Unrealized Losses	(7)
Other ABS [Member] | Asset-Backed Securities [Member] | Below Investment Grade [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	12
Total, Unrealized Losses	(3)
Other ABS [Member] | Asset-Backed Securities [Member] | Not Rated [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Fair Value	133
Total, Unrealized Losses	$ (43)