- Fair Value Level 3 Rollforward Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
FG VIEs' assets, at fair value [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	$ 700	$ 876
Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	2	37
Other comprehensive income (loss)	0	0
Purchases	0	0
Issuances	0
Settlements	(116)	(147)
FG VIE consolidations		39
FG VIE deconsolidations	(17)	(105)
Transfers into Level 3		0
Fair value at end of period	569	700
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	13	59
Other [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	64	65
Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	14	(2)
Other comprehensive income (loss)	0	0
Purchases	0	1
Issuances	0
Settlements	(1)	0
FG VIE consolidations		0
FG VIE deconsolidations	0	0
Transfers into Level 3		0
Fair value at end of period	77	64
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	14	(2)
Obligations of state and political subdivisions [Member] \| Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	76	39
Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	3	(13)
Other comprehensive income (loss)	18	(2)
Purchases	4	0
Issuances	0
Settlements	(2)	(2)
FG VIE consolidations		0
FG VIE deconsolidations	0	0
Transfers into Level 3		54
Fair value at end of period	99	76
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI		(2)
Corporate securities [Member] \| Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	67	60
Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	(14)	6
Other comprehensive income (loss)	3	1
Purchases	0	0
Issuances	0
Settlements	0	0
FG VIE consolidations		0
FG VIE deconsolidations	0	0
Transfers into Level 3		0
Fair value at end of period	56	67
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI		1
Residential Mortgage-Backed Securities (RMBS) [Member] \| Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	334	365
Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	21	27
Other comprehensive income (loss)	(17)	23
Purchases	35	42
Issuances	0
Settlements	(64)	(123)
FG VIE consolidations		0
FG VIE deconsolidations	0	0
Transfers into Level 3		0
Fair value at end of period	309	334
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI		23
Asset-backed Securities [Member] \| Fixed Maturities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	787	805
Acquisition		7
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	57	113
Other comprehensive income (loss)	(40)	56
Purchases	189	173
Issuances	0
Settlements	(46)	(367)
FG VIE consolidations		0
FG VIE deconsolidations	0	0
Transfers into Level 3		0
Fair value at end of period	947	787
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI		123
Other Comprehensive Income (Loss) [Member] \| Other [Member]
Total pretax realized and unrealized gains/(losses) recorded in:
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	0
Other Comprehensive Income (Loss) [Member] \| Obligations of state and political subdivisions [Member] \| Fixed Maturities [Member]
Total pretax realized and unrealized gains/(losses) recorded in:
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	18
Other Comprehensive Income (Loss) [Member] \| Corporate securities [Member] \| Fixed Maturities [Member]
Total pretax realized and unrealized gains/(losses) recorded in:
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	3
Other Comprehensive Income (Loss) [Member] \| Residential Mortgage-Backed Securities (RMBS) [Member] \| Fixed Maturities [Member]
Total pretax realized and unrealized gains/(losses) recorded in:
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	(14)
Other Comprehensive Income (Loss) [Member] \| Asset-backed Securities [Member] \| Fixed Maturities [Member]
Total pretax realized and unrealized gains/(losses) recorded in:
Change in unrealized gains/(losses) related to financial instruments held, Included in OCI	(38)
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	(627)	(807)
MBIA UK Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	(1)	(16)
Other comprehensive income (loss)	2	0
Purchases	0	0
Issuances	0
Settlements	108	145
FG VIE consolidations		0
FG VIE deconsolidations	1	51
Transfers into Level 3		0
Fair value at end of period	(517)	(627)
Change in unrealized gains/(losses) related to financial instruments held	1	(11)
FG VIEs' liabilities with recourse, at fair value [Member] \| Other Comprehensive Income (Loss) [Member]
Total pretax realized and unrealized gains/(losses) recorded in:
Change in unrealized gains/(losses) related to financial instruments held	2
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	(130)	(151)
MBIA UK Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	4	(6)
Other comprehensive income (loss)	0	0
Purchases	0	0
Issuances	0
Settlements	8	12
FG VIE consolidations		(39)
FG VIE deconsolidations	16	54
Transfers into Level 3		0
Fair value at end of period	(102)	(130)
Change in unrealized gains/(losses) related to financial instruments held	3	(6)
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	(269)	(389)
MBIA UK Acquisition		0
Total pretax realized and unrealized gains/(losses) recorded in:
Net income (loss)	112	107
Other comprehensive income (loss)	0	0
Purchases	0	0
Issuances	(68)
Settlements	18	13
FG VIE consolidations		0
FG VIE deconsolidations	0	0
Transfers into Level 3		0
Fair value at end of period	(207)	(269)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 122	$ 96

Fair Value, Measured with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Consolidation

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Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Acquired In Business Combination

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Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]

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Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

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Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those liabilities still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

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- Definition

Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19279-110258

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