Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	$ 827	$ 751	$ 774	$ 738
Capitalized deferred policy acquisition costs	306	295	601	565
Amortized deferred policy acquisition costs	(276)	(251)	(541)	(497)
Shadow deferred policy acquisition costs	(23)	(9)	0	(20)
Deferred policy acquisition costs asset, end of period	834	786	834	786
Consolidated Property and Casualty Insurance Entity
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	536	485	512	464
Capitalized deferred policy acquisition costs	292	280	572	534
Amortized deferred policy acquisition costs	(261)	(239)	(517)	(472)
Deferred policy acquisition costs asset, end of period	567	526	567	526
Life Insurance Segment
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	291	266	262	274
Capitalized deferred policy acquisition costs	14	15	29	31
Amortized deferred policy acquisition costs	(15)	(12)	(24)	(25)
Shadow deferred policy acquisition costs	(23)	(9)	0	(20)
Deferred policy acquisition costs asset, end of period	$ 267	$ 260	$ 267	$ 260