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		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	$ (12)	$ (7)	$ (54)	$ (113)
MBS with embedded derivatives | Realized gains on securities
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	0	(4)	(3)	0
Public company warrants | Realized gains on securities
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	(1)	1	(1)	0
Fixed-indexed annuities (embedded derivative) | Annuity benefits
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	(127)	(109)	(386)	(188)
Equity index call options | Annuity benefits
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	116	105	338	81
Reinsurance contracts (embedded derivative) | Net investment income
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Derivative	$ 0	$ 0	$ (2)	$ (6)