Comprehensive Income - Schedule of Changes in Balances of Each Component of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ (253)	$ 58
Other comprehensive income before reclassifications	(33)	127
Amounts reclassified from accumulated other comprehensive income	3	(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	36	(127)
Ending Balance	(217)	(70)
Income Tax Expense (Benefit)	4	0
Realized Investment Gains (Losses)	(4)	10
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(71)	154
Other comprehensive income before reclassifications	(14)	104
Amounts reclassified from accumulated other comprehensive income	4	(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	17	(105)
Ending Balance	(54)	49
Realized Investment Gains (Losses)	4	(1)
Accumulated Translation Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(184)	(100)
Other comprehensive income before reclassifications	(16)	23
Amounts reclassified from accumulated other comprehensive income	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	16	(23)
Ending Balance	(168)	(123)
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(1)	(1)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	0	0
Ending Balance	(1)	(1)
Other Postretirement Benefits Plan [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	3	4
Other comprehensive income before reclassifications	(3)	0
Amounts reclassified from accumulated other comprehensive income	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	3	0
Ending Balance	6	4
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Income Tax Expense (Benefit)	(1)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Other Postretirement Benefits Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0	0
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Amounts reclassified from accumulated other comprehensive income	0	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	0	0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	0
Income Tax Expense (Benefit)	$ 0	$ 0