Shareholders' Equity - Changes in AOCI by Component (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 6,639
New accounting pronouncement or change in accounting principle, effect of change on net income			$ 0
Other comprehensive income (loss) before reclassifications	(208)	$ 156
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	(5)	(12)
Income (loss) before income taxes	(62)	58
Tax (provision) benefit	4	(4)
Net current period other comprehensive income (loss)	(204)	168
Ending balance	6,240
Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	(5)	(12)
Net investment income	0
Fair value gains (losses) on FG VIEs	(2)	(2)
Income (loss) before income taxes	(7)	(14)
Tax (provision) benefit	3	2
Total amount reclassified from AOCI, net of tax	(4)	(12)
Total Accumulated Other Comprehensive Income [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	342	93
Amounts reclassified from AOCI to:
Ending balance	138	261
Net Unrealized Gains (Losses) on Investments with no OTTI [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	352	59
New accounting pronouncement or change in accounting principle, effect of change on net income			62
Other comprehensive income (loss) before reclassifications	(156)	165
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	(162)	163
Ending balance	252	222
Net Unrealized Gains (Losses) on Investments with no OTTI [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	6	3
Net investment income	0
Fair value gains (losses) on FG VIEs	0	0
Income (loss) before income taxes	6	3
Tax (provision) benefit	0	(1)
Total amount reclassified from AOCI, net of tax	6	2
Net Unrealized Gains (Losses) on Investments with OTTI [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	48	94
New accounting pronouncement or change in accounting principle, effect of change on net income			(62)
Other comprehensive income (loss) before reclassifications	(61)	(7)
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	(52)	5
Ending balance	(66)	99
Net Unrealized Gains (Losses) on Investments with OTTI [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	(11)	(15)
Net investment income	0
Fair value gains (losses) on FG VIEs	0	0
Income (loss) before income taxes	(11)	(15)
Tax (provision) benefit	2	3
Total amount reclassified from AOCI, net of tax	(9)	(12)
Net Unrealized Gains (Losses) on FG VIE Liabilities with Recourse due to Instrument Specific Credit Risk [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(27)	(31)
New accounting pronouncement or change in accounting principle, effect of change on net income			0
Other comprehensive income (loss) before reclassifications	9	(2)
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	10	0
Ending balance	(17)	(31)
Net Unrealized Gains (Losses) on FG VIE Liabilities with Recourse due to Instrument Specific Credit Risk [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0
Net investment income	0
Fair value gains (losses) on FG VIEs	(2)	(2)
Income (loss) before income taxes	(2)	(2)
Tax (provision) benefit	1	0
Total amount reclassified from AOCI, net of tax	(1)	(2)
Cumulative Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(38)	(37)
New accounting pronouncement or change in accounting principle, effect of change on net income			0
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	0	0
Ending balance	(38)	(37)
Cumulative Translation Adjustment [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0
Net investment income	0
Fair value gains (losses) on FG VIEs	0	0
Income (loss) before income taxes	0	0
Tax (provision) benefit	0	0
Total amount reclassified from AOCI, net of tax	0	0
Cash Flow Hedge [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	7	8
New accounting pronouncement or change in accounting principle, effect of change on net income			$ 0
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	0	0
Ending balance	7	8
Cash Flow Hedge [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0
Net investment income	0
Fair value gains (losses) on FG VIEs	0	0
Income (loss) before income taxes	0	0
Tax (provision) benefit	0	0
Total amount reclassified from AOCI, net of tax	$ 0	$ 0

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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