Summary of Net Operating Income (Loss) for Segments and Corporate and Other Activities (Parenthetical) (Detail) - Net Investment (Gains) Losses - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Adjustment for DAC and other intangibles and certain benefit reserves	$ (3)	$ (3)	$ (8)	$ (7)
Adjustment for portion attributable to noncontrolling interests	$ (4)	$ 1	$ 2	$ 2