Dispositions - Separation of Brighthouse - Ongoing Reinsurance Transactions (Effects of Reinsurance on Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Premiums:
Reinsurance assumed	$ 2,020	$ 2,021	$ 1,773
Reinsurance ceded	(2,298)	(2,380)	(2,376)
Net premiums	42,235	43,840	38,992
Fees and Commissions [Abstract] (Deprecated 2018-01-31)
Assumed Insurance Commissions And Fees	56	86	83
Ceded Insurance Commissions And Fees	(562)	(592)	(551)
Universal life and investment-type product policy fees	5,603	5,502	5,510
Policyholder benefits and claims:
Reinsurance assumed	1,584	1,583	1,388
Reinsurance ceded	(2,217)	(2,383)	(2,429)
Net policyholder benefits and claims	41,461	42,656	38,313
Interest Credited To Policyholder Account Balances [Abstract]
Policyholder Account Balance, Interest Expense	6,464	4,013	5,607
Other expenses:
Reinsurance assumed	382	321	246
Reinsurance ceded	252	311	235
Other expenses	13,689	13,714	13,621
Affiliated Entity [Member]
Premiums:
Reinsurance assumed	387	401	183
Reinsurance ceded	(8)	(13)	(4)
Net premiums	379	388	179
Fees and Commissions [Abstract] (Deprecated 2018-01-31)
Assumed Insurance Commissions And Fees	(16)	7	(4)
Ceded Insurance Commissions And Fees	(52)	(96)	(44)
Universal life and investment-type product policy fees	(68)	(89)	(48)
Policyholder benefits and claims:
Reinsurance assumed	323	328	150
Reinsurance ceded	(46)	(36)	(22)
Net policyholder benefits and claims	277	292	128
Interest Credited To Policyholder Account Balances [Abstract]
Assumed Interest Credited To Policyholders Account Balances	13	14	6
Ceded Interest Credited To Policyholders Account Balances	(75)	(71)	(30)
Policyholder Account Balance, Interest Expense	(62)	(57)	(24)
Other expenses:
Reinsurance assumed	96	105	39
Reinsurance ceded	17	29	(7)
Other expenses	$ 79	$ 76	46
Brighthouse Financial, Inc
Premiums:
Reinsurance assumed			248
Reinsurance ceded			(7)
Net premiums			241
Fees and Commissions [Abstract] (Deprecated 2018-01-31)
Assumed Insurance Commissions And Fees			(6)
Ceded Insurance Commissions And Fees			(55)
Universal life and investment-type product policy fees			(61)
Policyholder benefits and claims:
Reinsurance assumed			196
Reinsurance ceded			(16)
Net policyholder benefits and claims			180
Interest Credited To Policyholder Account Balances [Abstract]
Assumed Interest Credited To Policyholders Account Balances			10
Ceded Interest Credited To Policyholders Account Balances			(42)
Policyholder Account Balance, Interest Expense			(32)
Other expenses:
Reinsurance assumed			10
Reinsurance ceded			28
Other expenses			$ (18)