Level 4- Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Changes in fair value of assets using fair value option	$ 0	$ (1)
Fixed maturities, at fair value using the fair value option	38		$ 41
Assets, Fair Value Disclosure	39,482		40,297
Corporate
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Changes in fair value of assets using fair value option	0	$ (1)
RMBS
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fixed maturities, at fair value using the fair value option	38		41
Total fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	$ 38		$ 41