Investments - Change in unrealized net capital gains and losses (Details) $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	$ (4,506)
Amounts recognized for:
Other unrealized net capital gains and losses, pre-tax	27
Deferred income taxes	954
Decrease in unrealized net capital gains and losses, after-tax	(3,525)
EMA limited partnerships
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	8
Fixed income securities
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	(4,513)
Short-term investments
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	(1)
Derivative instruments
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	$ 0