Investments (Net Unrealized Investment Gains (Losses)) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Components of net unrealized investment gains (losses) included in accumulated other comprehensive loss
Fixed maturity securities	$ 10,185	$ 6,894
Derivatives	640	232
Other	(18)	(15)
Subtotal	10,807	7,111
Amounts allocated from: Future policy benefits	(4,516)	(2,691)
Amounts allocated from: DAC, VOBA and DSI	(426)	(332)
Subtotal	(4,942)	(3,023)
Deferred income tax benefit (expense)	(1,232)	(859)
Net unrealized investment gains (losses)	$ 4,633	$ 3,229