Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	$ 905	$ 805
Capitalized deferred policy acquisition costs	379	326
Amortized deferred policy acquisition costs	(311)	(277)
Shadow deferred policy acquisition costs	6	26
Deferred policy acquisition costs asset, end of period	979	880
Consolidated Property And Casualty Insurance
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	602	542
Capitalized deferred policy acquisition costs	364	312
Amortized deferred policy acquisition costs	(301)	(268)
Deferred policy acquisition costs asset, end of period	665	586
Life Insurance Segment
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	303	263
Capitalized deferred policy acquisition costs	15	14
Amortized deferred policy acquisition costs	(10)	(9)
Shadow deferred policy acquisition costs	6	26
Deferred policy acquisition costs asset, end of period	$ 314	$ 294