Investments - Change in unrealized net capital gains and losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses			$ 530
Amounts recognized for:
Reclassification of noncontrolling interest			(4)
Deferred income taxes			(116)
Increase in unrealized net capital gains and losses, after-tax	$ (272)	$ (1,144)	410	$ (2,738)
Limited partnership interests
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses			(2)
Fixed income securities
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses			531
Short-term investments
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses			0
Derivative instruments
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses			$ 1