Derivative Instruments (Hedged Item Offset By Derivatives Achieving Fair Value Hedge Accounting) (Details) - USD ($) $ in Millions		Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Fixed maturities, available-for-sale	[1]	$ 373,252	$ 412,905
Commercial mortgage and other loans	[1]	57,786	65,425
Policyholders’ account balances		(122,337)	(161,682)
Future policy benefits		(291,721)	(306,343)
Carrying Amount of the Hedged Assets (Liabilities)
Derivative [Line Items]
Fixed maturities, available-for-sale		418	402
Commercial mortgage and other loans		18	20
Policyholders’ account balances		(1,533)	(1,627)
Future policy benefits		(2,539)	(1,585)
Cumulative Adjustment Included in Carrying Amount
Derivative [Line Items]
Fixed maturities, available-for-sale		59	79
Commercial mortgage and other loans		1	2
Policyholders’ account balances		(166)	(303)
Future policy benefits		$ (252)	$ (372)

[1] See Note 4 for details of balances associated with variable interest entities.