Fair Value Measurement - Fair Value Level 3 Rollforward Recurring Basis (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Short-term Investments [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period		$ 60
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[1],[2]	0
Other comprehensive income (loss)	[2]	0
Purchases		0
Settlements		(60)
FG VIE Consolidations		0
FG VIE deconsolidations		0
Fair value at end of period		0
Change in unrealized gains/(losses) related to financial instruments held		0
FG VIEs' assets, at fair value [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period		1,261	$ 1,398
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[2],[3]	(4)	23
Other comprehensive income (loss)	[2]	0	0
Purchases		0	0
Settlements		(66)	(30)
FG VIE Consolidations		0	104
FG VIE deconsolidations		0	0
Fair value at end of period		1,191	1,495
Change in unrealized gains/(losses) related to financial instruments held		4	34
Other Assets and Other Invested Assets [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	[4]	65	37
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[2],[4],[5]	(16)	2
Other comprehensive income (loss)	[2],[4]	0	1
Purchases	[4]	0	0
Settlements	[4]	0	0
FG VIE Consolidations	[4]	0	0
FG VIE deconsolidations	[4]	0	0
Fair value at end of period	[4]	49	40
Change in unrealized gains/(losses) related to financial instruments held	[4]	(16)	3
Obligations of state and political subdivisions [Member] | Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period		8	38
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[1],[2]	0	3
Other comprehensive income (loss)	[2]	0	(2)
Purchases		0	0
Settlements		(1)	(31)	[6]
FG VIE Consolidations		0	0
FG VIE deconsolidations		0	0
Fair value at end of period		7	8
Change in unrealized gains/(losses) related to financial instruments held		0	0
Corporate securities [Member] | Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period		71	79
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[1],[2]	2	2
Other comprehensive income (loss)	[2]	1	(2)
Purchases		0	0
Settlements		0	0
FG VIE Consolidations		0	0
FG VIE deconsolidations		0	0
Fair value at end of period		74	79
Change in unrealized gains/(losses) related to financial instruments held		1	(2)
RMBS [Member] | Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period		348	425
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[1],[2]	(2)	9
Other comprehensive income (loss)	[2]	(5)	5
Purchases		34	9
Settlements		(15)	(65)
FG VIE Consolidations		0	0
FG VIE deconsolidations		0	0
Fair value at end of period		360	383
Change in unrealized gains/(losses) related to financial instruments held		(6)	7
Asset-backed Securities [Member] | Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period		657	228
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net Income (loss)	[1],[2]	1	(2)
Other comprehensive income (loss)	[2]	(5)	1
Purchases		0	0
Settlements		(14)	(1)
FG VIE Consolidations		0	0
FG VIE deconsolidations		0	0
Fair value at end of period		639	226
Change in unrealized gains/(losses) related to financial instruments held		(5)	1
FG VIEs' liabilities with recourse, at fair value [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period		(1,225)	(1,277)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Liabilities [Abstract]
Net income (loss)	[2],[3]	21	93
Other comprehensive income (loss)	[2]	0	0
Purchases		0	0
Settlements		39	37
FG VIE consolidations		0	(131)
FG VIE deconsolidations		0	0
Fair value at end of period		(1,165)	(1,278)
Change in unrealized gains/(losses) related to financial instruments held		21	(6)
FG VIEs' liabilities without recourse, at fair value [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period		(124)	(142)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Liabilities [Abstract]
Net income (loss)	[2],[3]	2	(5)
Other comprehensive income (loss)	[2]	0	0
Purchases		0	0
Settlements		3	2
FG VIE consolidations		0	0
FG VIE deconsolidations		0	0
Fair value at end of period		(119)	(145)
Change in unrealized gains/(losses) related to financial instruments held		1	(4)
Credit Risk Contract [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value at beginning of period	[7]	(365)	(895)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Net Derivative Asset (Liability) [Abstract]
Net income (loss)	[2],[7],[8]	(60)	124
Other comprehensive income (loss)	[2],[7]	0	0
Purchases	[7]	0	0
Settlements	[7]	(9)	(11)
FG VIE consolidations	[7]	0	0
FG VIE deconsolidations	[7]	0	0
Fair value at end of period	[7]	(434)	(782)
Change in unrealized gains/(losses) related to financial instruments held	[7]	$ (79)	$ 103

[1] Included in net realized investment gains (losses) and net investment income.

[2] Realized and unrealized gains (losses) from changes in values of Level 3 financial instruments represent gains (losses) from changes in values of those financial instruments only for the periods in which the instruments were classified as Level 3.

[3] Included in fair value gains (losses) on FG VIEs.

[4] Includes CCS and other invested assets.

[5] Recorded in fair value gains (losses) on CCS, net investment income and other income.

[6] Primarily non-cash transaction.

[7] Represents net position of credit derivatives. The consolidated balance sheet presents gross assets and liabilities based on net counterparty exposure.

[8] Reported in net change in fair value of credit derivatives.