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	$ 10,305	$ 6,957
Derivatives	660	245
Other	(16)	(13)
Subtotal	10,949	7,189
Amounts allocated from: Future policy benefits	(4,153)	(2,692)
Amounts allocated from: DAC, VOBA and DSI	(445)	(341)
Subtotal	(4,598)	(3,033)
Deferred income tax benefit (expense)	(1,334)	(873)
Net unrealized investment gains (losses)	$ 5,017	$ 3,283