Investments (Net Unrealized Investment Gains (Losses)) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Components of net unrealized investment gains (losses) included in accumulated other comprehensive loss
Fixed maturity securities	$ 11,150	$ 6,894
Derivatives	448	232
Other	(17)	(15)
Subtotal	11,581	7,111
Amounts allocated from: Future policy benefits	(4,631)	(2,691)
Amounts allocated from: DAC, VOBA and DSI	(462)	(332)
Subtotal	(5,093)	(3,023)
Deferred income tax benefit (expense)	(1,363)	(859)
Net unrealized investment gains (losses)	$ 5,125	$ 3,229