Other Comprehensive Income - Changes in AOCI by Component (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				$ 6,555					$ 6,555
Reclassification of stranded tax effects											$ 56
Other comprehensive income (loss) before reclassifications										$ (279)	212
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)	$ 10	$ 16	$ 8	(12)	$ (18)	$ (7)	$ (2)	$ (5)	22	(32)	40
Net investment income	82	88	110	98	98	99	98	100	378	395	417
Interest expense	(22)	(22)	(22)	(23)	(23)	(23)	(24)	(24)	(89)	(94)	(97)
Income (loss) before income taxes	138	86	182	58	101	175	87	217	464	580	991
Total (provision) benefit for income taxes	(2)	$ (17)	$ (40)	(4)	(13)	$ (14)	$ (12)	(20)	(63)	(59)	(261)
Total amount reclassified from AOCI, net of tax										(32)	45
Net current period other comprehensive income (loss)									249	(247)	167
Ending balance	6,639				6,555				6,639	6,555
Accounting Standards Update 2016-01 [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Effect of adoption of ASU 2016-01												$ 32
Reclassification out of Accumulated Other Comprehensive Income [Member]
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)										(31)	40
Net investment income											28
Fair value gains (losses) on FG VIEs										(9)
Interest expense										0	1
Income (loss) before income taxes										(40)	69
Total (provision) benefit for income taxes										8	(24)
Total AOCI
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				93				372	93	372	149
Other comprehensive income (loss) before reclassifications									268
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)									23
Net investment income									16
Fair value gains (losses) on FG VIEs									(15)
Interest expense									1
Income (loss) before income taxes									25
Total (provision) benefit for income taxes									(6)
Total amount reclassified from AOCI, net of tax									19
Net current period other comprehensive income (loss)									249
Ending balance	342				93				342	93	372
Net Unrealized Gains (Losses) on Investments with no OTTI [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				59				273	59	273	171
Reclassification of stranded tax effects											38
Other comprehensive income (loss) before reclassifications									339	(208)	128
Less: Amounts reclassified from AOCI to:
Total amount reclassified from AOCI, net of tax									46	7	64
Net current period other comprehensive income (loss)									293	(215)	64
Ending balance	352				59				352	59	273
Net Unrealized Gains (Losses) on Investments with no OTTI [Member] | Accounting Standards Update 2016-01 [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Effect of adoption of ASU 2016-01												(1)
Net Unrealized Gains (Losses) on Investments with no OTTI [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)									55	7	71
Net investment income									1		27
Fair value gains (losses) on FG VIEs									0	0
Interest expense									0	0	0
Income (loss) before income taxes									56	7	98
Total (provision) benefit for income taxes									(10)	0	(34)
Net Unrealized Gains (Losses) on Investments with OTTI [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				94				120	94	120	10
Reclassification of stranded tax effects											21
Other comprehensive income (loss) before reclassifications									(62)	(58)	69
Less: Amounts reclassified from AOCI to:
Total amount reclassified from AOCI, net of tax									(16)	(32)	(20)
Net current period other comprehensive income (loss)									(46)	(26)	89
Ending balance	48				94				48	94	120
Net Unrealized Gains (Losses) on Investments with OTTI [Member] | Accounting Standards Update 2016-01 [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Effect of adoption of ASU 2016-01												0
Net Unrealized Gains (Losses) on Investments with OTTI [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)									(32)	(38)	(31)
Net investment income									15		1
Fair value gains (losses) on FG VIEs									0	0
Interest expense									0	0	0
Income (loss) before income taxes									(17)	(38)	(30)
Total (provision) benefit for income taxes									1	6	10
Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				(31)				0	(31)	0
Other comprehensive income (loss) before reclassifications									(8)	(5)
Less: Amounts reclassified from AOCI to:
Total amount reclassified from AOCI, net of tax									(12)	(7)
Net current period other comprehensive income (loss)									4	2
Ending balance	(27)				(31)				(27)	(31)	0
Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR [Member] | Accounting Standards Update 2016-01 [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Effect of adoption of ASU 2016-01												33
Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)									0	0
Net investment income									0
Fair value gains (losses) on FG VIEs									(15)	(9)
Interest expense									0	0
Income (loss) before income taxes									(15)	(9)
Total (provision) benefit for income taxes									3	2
Cumulative Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				(37)				(29)	(37)	(29)	(39)
Reclassification of stranded tax effects											(5)
Other comprehensive income (loss) before reclassifications									(1)	(8)	15
Less: Amounts reclassified from AOCI to:
Total amount reclassified from AOCI, net of tax									0	0	0
Net current period other comprehensive income (loss)									(1)	(8)	15
Ending balance	(38)				(37)				(38)	(37)	(29)
Cumulative Translation Adjustment [Member] | Accounting Standards Update 2016-01 [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Effect of adoption of ASU 2016-01												0
Cumulative Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)									0	0	0
Net investment income									0		0
Fair value gains (losses) on FG VIEs									0	0
Interest expense									0	0	0
Income (loss) before income taxes									0	0	0
Total (provision) benefit for income taxes									0	0	0
Cash Flow Hedge [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance				$ 8				$ 8	8	8	7
Reclassification of stranded tax effects											2
Other comprehensive income (loss) before reclassifications									0	0	0
Less: Amounts reclassified from AOCI to:
Total amount reclassified from AOCI, net of tax									1	0	1
Net current period other comprehensive income (loss)									(1)	0	(1)
Ending balance	$ 7				$ 8				7	8	8
Cash Flow Hedge [Member] | Accounting Standards Update 2016-01 [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Effect of adoption of ASU 2016-01												$ 0
Cash Flow Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Less: Amounts reclassified from AOCI to:
Net realized investment gains (losses)									0	0	0
Net investment income									0		0
Fair value gains (losses) on FG VIEs									0	0
Interest expense									1	0	1
Income (loss) before income taxes									1	0	1
Total (provision) benefit for income taxes									$ 0	$ 0	$ 0