Consolidated Variable Interest Entities - Narrative (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($) Entity	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) Entity	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) Entity		Dec. 31, 2014 USD ($) Entity		Dec. 31, 2013 USD ($) Entity		Dec. 31, 2012 Entity
Variable Interest Entity [Line Items]
Net fair value gains and losses on FG VIEs are expected to reverse to zero at maturity of the VIE debt	$ 0								$ 0
Trustee report general preparation period									30 days
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Fair value gains (losses) on FG VIEs	38,000,000	$ 2,000,000	$ 5,000,000	$ (7,000,000)	$ 23,000,000	$ 50,000,000	$ 25,000,000	$ 157,000,000	$ 38,000,000		$ 255,000,000
Number of entities to be deconsolidated | Entity											7
Number of FG VIE's matured | Entity											(2)
Net earned premiums	$ 192,000,000	$ 213,000,000	$ 219,000,000	$ 142,000,000	$ 158,000,000	$ 144,000,000	$ 136,000,000	132,000,000	766,000,000	[1]	$ 570,000,000	[1]	$ 752,000,000	[1]
Variable Interest Entity, Primary Beneficiary [Member]
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Fair value gains (losses) on FG VIEs									$ 38,000,000		255,000,000		$ 346,000,000
Gain from Company's exercise of options											37,000,000
Net gain on deconsolidation								$ 120,000,000			$ 120,000,000
Number of FG VIE's matured | Entity									(2)		(2)		(1)
Net earned premiums									$ (21,000,000)		$ (32,000,000)		$ (60,000,000)
Number of VIE that did not require consolidation | Entity	34				32				34		32		40		33
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member]
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Number of VIE that did not require consolidation | Entity	750				930				750		930
Residential Mortgage Backed Securities and Other Insurance Products [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Total unpaid principal balance for the VIEs' assets that were over 90 days or more past due	$ 154,000,000				$ 183,000,000				$ 154,000,000		$ 183,000,000
Difference between the aggregate unpaid principal and aggregate fair value of the VIEs' Assets	804,000,000				941,000,000				804,000,000		941,000,000
Change in the instrument specific credit risk of the VIEs' assets									90,000,000		116,000,000		$ 340,000,000
Unpaid principal for FG VIEs’ liabilities with recourse	1,436,000,000				1,912,000,000				1,436,000,000		1,912,000,000
Unpaid principal for FG VIEs' liabilities with and without recourse	$ 423,000,000				$ 916,000,000				$ 423,000,000		$ 916,000,000
Various counterparties [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Fair value gains (losses) on FG VIEs													$ 265,000,000

[1] Excludes $21 million, $32 million and $60 million for the year ended December 31, 2015, 2014 and 2013, respectively, related to consolidated FG VIEs.