Investments - Change in unrealized net capital gains and losses (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	$ 1,335
Amount recognized for:
Insurance reserves	(8)
DAC and DSI	(91)
Amounts recognized	(99)
Deferred income taxes	(262)
Increase in unrealized net capital gains and losses, after-tax	974
Fixed income securities
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	1,335
Derivatives
Change in Unrealized Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Loss)
Change in unrealized net capital gains and losses	$ 0