Fair Value - Changes in Level 3 Financial Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 164	$ 108
Net realized and unrealized capital gains (losses):
Included in net income	33	23
Included in other comprehensive income	(2)	(1)
Purchases	134	101
Sales	(39)	0
Transfers out of level 3, net	(86)	(67)
Ending balance	$ 204	$ 164
Fair Value Recurring Basis, Unobservable Input Reconciliation Asset Gain (Loss), Statement Of Income, Extensible List, Not Disclosed Flag	Included in net income	Included in net income
Commercial mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 0	$ 0
Net realized and unrealized capital gains (losses):
Included in net income	0	0
Included in other comprehensive income	0	0
Purchases	19	52
Sales	0	0
Transfers out of level 3, net	(19)	(52)
Ending balance	0	0
U.S. corporate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	38	29
Net realized and unrealized capital gains (losses):
Included in net income	7	(5)
Included in other comprehensive income	(2)	(1)
Purchases	40	15
Sales	(33)	0
Transfers out of level 3, net	(44)	0
Ending balance	6	38
Other asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	0
Net realized and unrealized capital gains (losses):
Included in net income		0
Included in other comprehensive income		0
Purchases		15
Sales		0
Transfers out of level 3, net		(15)
Ending balance		0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	126	79
Net realized and unrealized capital gains (losses):
Included in net income	26	28
Included in other comprehensive income	0	0
Purchases	52	19
Sales	(6)	0
Transfers out of level 3, net	0	0
Ending balance	198	126
Redeemable preferred securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0
Net realized and unrealized capital gains (losses):
Included in net income	0
Included in other comprehensive income	0
Purchases	23
Sales	0
Transfers out of level 3, net	(23)
Ending balance	$ 0	$ 0