Derivatives - Gain (loss) included in the Statement of Earnings for changes in the fair value of derivatives that do not qualify for hedge accounting (Details) - Not Designated as Hedging Instrument - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	$ 21	$ (7)
MBS with embedded derivatives | Realized gains on securities
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	(4)	0
Public company warrants | Realized gains on securities
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	(1)	0
Fixed-indexed annuities (embedded derivative) | Annuity benefits
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	63	(147)
Equity index call options | Annuity benefits
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	(38)	141
Reinsurance contracts (embedded derivative) | Net investment income
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	$ 1	$ (1)