Accumulated Other Comprehensive (Loss) Income - Reconciliation of the Components of Accumulated Other Comprehensive Loss (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income attributable to noncontrolling interests, tax	$ 0	$ 0
Net gain (loss) recognized in other comprehensive income, tax (expense) benefit	15	(106)
Other comprehensive income attributable to noncontrolling interests	0	(2)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Including Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax	50	(85)
Reclassification from AOCI, current period, tax	33	29
Non-credit components of impairments on investments:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net gain (loss) recognized in other comprehensive income, tax (expense) benefit	0	1
Net cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net gain (loss) recognized in other comprehensive income, tax (expense) benefit	(1)	8
Pension and other postretirement benefits:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net gain (loss) recognized in other comprehensive income, tax (expense) benefit	(1)	(1)
Future policy benefits:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net gain (loss) recognized in other comprehensive income, tax (expense) benefit	0	0
Foreign currency translation adjustments:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net gain (loss) recognized in other comprehensive income, tax (expense) benefit	0	0
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income attributable to noncontrolling interests, tax	0	0
Other comprehensive income attributable to noncontrolling interests	$ 0	$ (2)