Schedule III - Supplementary Insurance Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	$ 2,226	$ 2,973
Future Policy Benefits and Contract Owner Account Balances	50,868	50,770
Unearned Premiums	(1)	(1)
Net Investment Income	2,792	2,669	$ 2,641
Premiums and Fee Income	4,242	4,114	3,986
Interest Credited and Other Benefits to Contract Owners	3,750	3,526	3,658
Amortization of DAC and VOBA	199	233	353
Other Operating Expenses	2,746	2,606	2,562
Premiums Written (Excluding Life)	1,361	1,187	1,155
Retirement
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	667	1,271
Future Policy Benefits and Contract Owner Account Balances	34,008	34,064
Unearned Premiums	0	0
Net Investment Income	2,029	1,971	1,918
Premiums and Fee Income	881	879	750
Interest Credited and Other Benefits to Contract Owners	1,067	908	1,043
Amortization of DAC and VOBA	96	117	238
Other Operating Expenses	1,373	1,284	1,140
Premiums Written (Excluding Life)	0	0	0
Investment Management
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	0	1
Future Policy Benefits and Contract Owner Account Balances	0	0
Unearned Premiums	0	0
Net Investment Income	12	(27)	(33)
Premiums and Fee Income	641	663	675
Interest Credited and Other Benefits to Contract Owners	0	0	0
Amortization of DAC and VOBA	4	3	3
Other Operating Expenses	565	555	558
Premiums Written (Excluding Life)	0	0	0
Employee Benefits
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	117	99
Future Policy Benefits and Contract Owner Account Balances	2,133	2,109
Unearned Premiums	(1)	(1)
Net Investment Income	112	113	108
Premiums and Fee Income	1,920	1,741	1,663
Interest Credited and Other Benefits to Contract Owners	1,405	1,317	1,293
Amortization of DAC and VOBA	16	17	11
Other Operating Expenses	406	356	336
Premiums Written (Excluding Life)	1,361	1,187	1,155
Corporate
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	1,442	1,602
Future Policy Benefits and Contract Owner Account Balances	14,727	14,597
Unearned Premiums	0	0
Net Investment Income	639	612	648
Premiums and Fee Income	800	831	898
Interest Credited and Other Benefits to Contract Owners	1,278	1,301	1,322
Amortization of DAC and VOBA	83	96	101
Other Operating Expenses	402	411	528
Premiums Written (Excluding Life)	$ 0	$ 0	$ 0