Income Taxes - Components of Net Deferred Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Unearned premium reserves, net	$ 98	$ 124
Investment basis differences	49	63
Foreign tax credit	36	43
Net operating loss	34	38
Deferred compensation	25	21
Alternative minimum tax credit	20	59
FG VIEs	9	13
Unrealized losses on credit derivative financial instruments, net	6	20
Other	20	14
Total deferred income tax assets	297	395
Deferred tax liabilities:
Unrealized appreciation on investments	54	91
Public debt	50	53
Market discount	31	28
DAC	23	12
Unrealized gains on CCS	16	13
Loss and LAE reserve	7	27
Other	12	30
Total deferred income tax liabilities	193	254
Less: Valuation allowance	36	43
Net deferred income tax asset	$ 68	$ 98