Certain Long-Duration Contracts with Guarantees (Liabilities for Guarantee Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
GMDB | Variable Life, Variable Universal Life and Universal Life Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	$ 5,418	$ 5,110	$ 4,143
Incurred guarantee benefits	1,492	791	685
Paid guarantee benefits	(111)	(77)	(15)
Change in unrealized investment gains and losses	805	(406)	290
Other	(2)	0	7
Ending balance	7,602	5,418	5,110
GMDB | Annuity Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	713	697	721
Incurred guarantee benefits	82	125	37
Paid guarantee benefits	(69)	(88)	(74)
Change in unrealized investment gains and losses	27	(20)	13
Other	0	(1)	0
Ending balance	753	713	697
GMIB | Annuity Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	378	419	474
Incurred guarantee benefits	(8)	(14)	(20)
Paid guarantee benefits	(4)	(5)	(15)
Change in unrealized investment gains and losses	(15)	(20)	(30)
Other	4	(2)	10
Ending balance	355	378	419
GMAB/GMWB/GMIWB | Annuity Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	8,927	8,721	8,238
Incurred guarantee benefits	3,905	206	479
Paid guarantee benefits	0	0	0
Change in unrealized investment gains and losses	0	0	0
Other	(1)	0	4
Ending balance	$ 12,831	$ 8,927	$ 8,721