Closed Block (Revenues and Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues
Premiums	$ 1,672	$ 1,736	$ 1,804
Net investment income	1,758	1,818	1,902
Net investment gains (losses)	(71)	1	(10)
Net derivative gains (losses)	22	(32)	25
Total revenues	3,381	3,523	3,721
Expenses
Policyholder benefits and claims	2,475	2,453	2,563
Policyholder dividends	968	976	953
Other expenses	117	125	133
Total expenses	3,560	3,554	3,649
Revenues, net of expenses before provision for income tax expense (benefit)	(179)	(31)	72
Provision for income tax expense (benefit)	(39)	12	24
Revenues, net of expenses and provision for income tax expense (benefit)	$ (140)	$ (43)	$ 48