Value of Business Acquired (Balance of and Changes in VOBA) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, beginning of period	$ 1,850	$ 1,591	$ 2,314
Amortization—Impact of assumption and experience unlocking and true-ups	(139)	0	(56)
Amortization—All other	(235)	(276)	(311)
Change in unrealized investment gains and losses	(478)	455	(456)
Interest	64	69	75
Foreign currency translation	10	23	25
Other	38	(12)	0
Balance, end of period	1,110	$ 1,850	$ 1,591
CIGNA
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, end of period	226
Prudential Annuities Holding Co.
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, end of period	32
Gibraltar Life
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, end of period	848
Gibraltar BSN Life Berhad
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, end of period	4
Aoba Life
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, end of period	0
The Hartford Life Business
Movement in Present Value of Future Insurance Profits [Roll Forward]
Balance, end of period	$ 0