Shareholders' Equity - Changes in AOCI by Component (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			$ 6,639
Other comprehensive income (loss) before reclassifications	$ 85	$ 34	74	$ 237
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	13	16	12	12
Income (loss) before income taxes	79	86	239	326
Tax (provision) benefit	10	(17)	(20)	(61)
Net current period other comprehensive income (loss)	71	24	62	226
Ending balance	6,549		6,549
Reclassification out of Accumulated Other Comprehensive Income
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	13	17	12	13
Net investment income				16
Fair value gains (losses) on FG VIEs	4	(3)	1	(13)
Income (loss) before income taxes	17	14	13	16
Tax (provision) benefit	(3)	(4)	(1)	(5)
Total amount reclassified from AOCI, net of tax	14	10	12	11
Total Accumulated Other Comprehensive Income [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	333	295		93
Amounts reclassified from AOCI to:
Ending balance	404	319	404	319
Net Unrealized Gains (Losses) on Investments with no Credit Impairment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	427	301		59
Other comprehensive income (loss) before reclassifications	74	57	102	312
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	67	33	80	275
Ending balance	494	334	494	334
Net Unrealized Gains (Losses) on Investments with no Credit Impairment | Reclassification out of Accumulated Other Comprehensive Income
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	8	29	26	43
Net investment income				2
Fair value gains (losses) on FG VIEs	0	0	0	0
Income (loss) before income taxes	8	29	26	45
Tax (provision) benefit	(1)	(5)	(4)	(8)
Total amount reclassified from AOCI, net of tax	7	24	22	37
Net Unrealized Gains (Losses) on Investments with Credit Impairment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(41)	51		94
Other comprehensive income (loss) before reclassifications	12	(21)	(30)	(68)
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	8	(9)	(19)	(52)
Ending balance	(33)	42	(33)	42
Net Unrealized Gains (Losses) on Investments with Credit Impairment | Reclassification out of Accumulated Other Comprehensive Income
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	5	(12)	(14)	(30)
Net investment income				14
Fair value gains (losses) on FG VIEs	0	0	0	0
Income (loss) before income taxes	5	(12)	(14)	(16)
Tax (provision) benefit	(1)	0	3	0
Total amount reclassified from AOCI, net of tax	4	(12)	(11)	(16)
Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(22)	(27)		(31)
Other comprehensive income (loss) before reclassifications	(1)	(2)	2	(6)
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	(4)	0	1	4
Ending balance	(26)	(27)	(26)	(27)
Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR | Reclassification out of Accumulated Other Comprehensive Income
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0	0	0
Net investment income				0
Fair value gains (losses) on FG VIEs	4	(3)	1	(13)
Income (loss) before income taxes	4	(3)	1	(13)
Tax (provision) benefit	(1)	1	0	3
Total amount reclassified from AOCI, net of tax	3	(2)	1	(10)
Cumulative Translation Adjustment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(38)	(38)		(37)
Other comprehensive income (loss) before reclassifications	0	0	0	(1)
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	0	0	0	(1)
Ending balance	(38)	(38)	(38)	(38)
Cumulative Translation Adjustment | Reclassification out of Accumulated Other Comprehensive Income
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0	0	0
Net investment income				0
Fair value gains (losses) on FG VIEs	0	0	0	0
Income (loss) before income taxes	0	0	0	0
Tax (provision) benefit	0	0	0	0
Total amount reclassified from AOCI, net of tax	0	0	0	0
Cash Flow  Hedge
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	7	8		8
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	0	0	0	0
Ending balance	7	8	7	8
Cash Flow  Hedge | Reclassification out of Accumulated Other Comprehensive Income
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0	0	0
Net investment income				0
Fair value gains (losses) on FG VIEs	0	0	0	0
Income (loss) before income taxes	0	0	0	0
Tax (provision) benefit	0	0	0	0
Total amount reclassified from AOCI, net of tax	$ 0	$ 0	0	$ 0
Previously Reported | Total Accumulated Other Comprehensive Income [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			342
Previously Reported | Net Unrealized Gains (Losses) on Investments with no Credit Impairment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			352
Previously Reported | Net Unrealized Gains (Losses) on Investments with Credit Impairment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			48
Previously Reported | Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			(27)
Previously Reported | Cumulative Translation Adjustment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			(38)
Previously Reported | Cash Flow  Hedge
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			7
Revision of Prior Period, Adjustment | Total Accumulated Other Comprehensive Income [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			0
Revision of Prior Period, Adjustment | Net Unrealized Gains (Losses) on Investments with no Credit Impairment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			62
Revision of Prior Period, Adjustment | Net Unrealized Gains (Losses) on Investments with Credit Impairment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			(62)
Revision of Prior Period, Adjustment | Net Unrealized Gains (Losses) on FG VIEs’ Liabilities with Recourse due to ISCR
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			0
Revision of Prior Period, Adjustment | Cumulative Translation Adjustment
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			0
Revision of Prior Period, Adjustment | Cash Flow  Hedge
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			$ 0