Schedule of Pre-Tax Gain (Loss) Recognized in Net Income (Loss) for Effects of Derivatives not Designated as Hedges (Detail) - Derivatives not designated as hedges - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	$ (29)	$ (80)	$ (31)
Interest rate swaps | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	(11)	(3)	3
Equity index options | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	4	43	(34)
Financial futures | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	2	(64)	26
Equity return swaps | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	0	0	(4)
Other foreign currency contracts | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	38	(8)	4
GMWB embedded derivatives | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	(28)	38	(54)
Fixed index annuity embedded derivatives | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	(51)	(90)	15
Indexed universal life embedded derivatives | Net Investment Gains (Losses)
Derivative [Line Items]
Pre-tax gain (loss) recognized in net loss	$ 17	$ 4	$ 13