Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	$ 979	$ 880	$ 905	$ 805
Capitalized deferred policy acquisition costs	390	340	769	666
Amortized deferred policy acquisition costs	(328)	(295)	(639)	(572)
Shadow deferred policy acquisition costs	4	(1)	10	25
Deferred policy acquisition costs asset, end of period	1,045	924	1,045	924
Consolidated Property And Casualty Insurance
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	665	586	602	542
Capitalized deferred policy acquisition costs	375	325	739	637
Amortized deferred policy acquisition costs	(317)	(281)	(618)	(549)
Deferred policy acquisition costs asset, end of period	723	630	723	630
Life Insurance Segment
Movement Analysis of Deferred Policy Acquisition Costs
Deferred policy acquisition costs asset, beginning of period	314	294	303	263
Capitalized deferred policy acquisition costs	15	15	30	29
Amortized deferred policy acquisition costs	(11)	(14)	(21)	(23)
Shadow deferred policy acquisition costs	4	(1)	10	25
Deferred policy acquisition costs asset, end of period	$ 322	$ 294	$ 322	$ 294