Level 4 - Net Realized Capital Gains (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule of Investments [Line Items]
Gross gains on sales	$ 13	$ 21
Gross losses on sales	(8)	(17)
Transactional foreign currency revaluation	0	(14)
Total net realized capital gains (losses)	(193)	21
Proceeds from Sale of Available-for-sale Securities	945	1,100
GMWB Derivatives, Net [Member]
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives	14	4
Macro Hedge Program [Member]
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives	(226)	18
Other investments
Schedule of Investments [Line Items]
Other, net	16	(19)
Non-qualifying
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives	(204)	34
Variable Annuity [Member]
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives	(212)	22
Foreign Exchange Forward [Member] | Non-qualifying
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives	(4)	17
Derivative Instruments, Excluding Foreign Currency Derivatives [Member]
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives		(5)
Derivative Instruments, Excluding Foreign Currency Derivatives [Member] | Non-qualifying
Schedule of Investments [Line Items]
Non-qualifying foreign currency derivatives	12	(5)
Equity Securities [Member]
Schedule of Investments [Line Items]
Marketable Securities	2	11
Unrealized Gain (Loss) on Securities	8
Accumulated Net Unrealized Investment Gain (Loss) | Reclassification out of Accumulated Other Comprehensive Income
Schedule of Investments [Line Items]
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	$ 6	$ 4