Closed Block (Closed Block Revenues and Benefits and Expenses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues
Premiums	$ 480	$ 527
Net investment income	548	565
Realized investment gains (losses), net	256	56
Other income (loss)	(603)	228
Total Closed Block revenues	681	1,376
Benefits and Expenses
Policyholders’ benefits	647	709
Interest credited to policyholders’ account balances	32	32
Dividends to policyholders	(94)	553
General and administrative expenses	85	89
Total Closed Block benefits and expenses	670	1,383
Closed Block revenues, net of Closed Block benefits and expenses, before income taxes	11	(7)
Income tax expense (benefit)	(6)	(24)
Closed Block revenues, net of Closed Block benefits and expenses and income taxes	$ 17	$ 17