Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	$ 774	$ 738
Capitalized deferred policy acquisition costs	295	270
Amortized deferred policy acquisition costs	(265)	(246)
Shadow deferred policy acquisition costs	23	(11)
Deferred policy acquisition costs asset, end of period	827	751
Consolidated Property and Casualty Insurance Entity
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	512	464
Capitalized deferred policy acquisition costs	280	254
Amortized deferred policy acquisition costs	(256)	(233)
Deferred policy acquisition costs asset, end of period	536	485
Life Insurance Segment
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	262	274
Capitalized deferred policy acquisition costs	15	16
Amortized deferred policy acquisition costs	(9)	(13)
Shadow deferred policy acquisition costs	23	(11)
Deferred policy acquisition costs asset, end of period	$ 291	$ 266