Fair Value Measurements - Changes in Level 3 Assets and Liabilities (Details) (General Accounts [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
GMIB Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ (922)		$ (1,332)		$ (1,170)		$ (1,333)
Gains (losses) included in shareholders' net income:
GMIB fair value gain/(loss)	81		131		286		98
Other	(16)		0		(16)		0
Total gains (losses) included in shareholders' net income	65		131		270		98
Gains (losses) included in other comprehensive income	0		0		0		0
Gains (losses) required to adjust future policy benefits for settlement annuities	0	[1]	0	[1]	0	[1]	0	[1]
Purchases, issuances, settlements:
Purchases	0		0		0		0
Sales	0				0
Settlements	16		17		59		51
Total purchases, sales, and settlements	16		17		59		51
Transfers into/(out of) Level 3:
Transfer into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Transfers into/(out of) Level 3	0		0		0		0
Ending Balance	(841)		(1,184)		(841)		(1,184)
Total gains (losses) included in income attributable to instruments held at the reporting date	65		131		270		98
GMIB Net [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	23		(625)		(548)		(621)
Gains (losses) included in shareholders' net income:
GMIB fair value gain/(loss)	0		53		0		33
Other	(6)		0		(4)		0
Total gains (losses) included in shareholders' net income	(6)		53		(4)		33
Gains (losses) included in other comprehensive income	0		0		0		0
Gains (losses) required to adjust future policy benefits for settlement annuities	0	[1]	0	[1]	0	[1]	0	[1]
Purchases, issuances, settlements:
Purchases	0		0		0		0
Sales	0				0
Settlements	(5)		13		564		29
Total purchases, sales, and settlements	(5)		13		564		29
Transfers into/(out of) Level 3:
Transfer into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Transfers into/(out of) Level 3	0		0		0		0
Ending Balance	12		(559)		12		(559)
Total gains (losses) included in income attributable to instruments held at the reporting date	(6)		53		(4)		33
Fixed Maturities And Equity Securities [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,209		1,128		1,351		1,002
Gains (losses) included in shareholders' net income:
GMIB fair value gain/(loss)	0		0		0		0
Other	3		1		13		4
Total gains (losses) included in shareholders' net income	3		1		13		4
Gains (losses) included in other comprehensive income	(1)		11		(18)		16
Gains (losses) required to adjust future policy benefits for settlement annuities	(8)	[1]	(15)	[1]	(46)	[1]	(19)	[1]
Purchases, issuances, settlements:
Purchases	64		39		104		106
Sales	(18)				(48)
Settlements	(35)		(15)		(96)		(44)
Total purchases, sales, settlements	11		24		(40)		62
Transfers into/(out of) Level 3:
Transfers into Level 3	32		36		101		155
Transfers out of Level 3	(20)		(4)		(135)		(39)
Total transfers into/(out of) Level 3	12		32		(34)		116
Ending Balance	1,226		1,181		1,226		1,181
Total gains (losses) included in income attributable to instruments held at the reporting date	2		2		6		2
GMIB Assets [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	945		707		622		712
Gains (losses) included in shareholders' net income:
GMIB fair value gain/(loss)	(81)		(78)		(286)		(65)
Other	10		0		12		0
Total gains (losses) included in shareholders' net income	(71)		(78)		(274)		(65)
Gains (losses) included in other comprehensive income	0		0		0		0
Gains (losses) required to adjust future policy benefits for settlement annuities	0	[1]	0	[1]	0	[1]	0	[1]
Purchases, issuances, settlements:
Purchases	0		0		0		0
Sales	0				0
Settlements	(21)		(4)		505		(22)
Total purchases, sales, settlements	(21)		(4)		505		(22)
Transfers into/(out of) Level 3:
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Total transfers into/(out of) Level 3	0		0		0		0
Ending Balance	853		625		853		625
Total gains (losses) included in income attributable to instruments held at the reporting date	$ (71)		$ (78)		$ (274)		$ (65)

[1] Amounts do not accrue to shareholders.