Changes in Liability for Policy and Contract Claims (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Beginning balance	$ 10,958
Ending balance	11,373
Long-term Care Insurance
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Beginning balance	10,958	$ 10,295
Less reinsurance recoverables	(2,406)	(2,379)
Net beginning balance	8,552	7,916
Current year	3,179	2,865
Prior years	(389)	(237)
Total incurred	2,790	2,628
Current year	(708)	(659)
Prior years	(1,867)	(1,794)
Total paid	(2,575)	(2,453)
Interest on liability for policy and contract claims	308	285
Foreign currency translation	5	(9)
Net ending balance	9,080	8,367
Add reinsurance recoverables	2,293	2,413
Ending balance	$ 11,373	$ 10,780