POLICY LIABILITIES - Changes in Liability for Unpaid Policy Claims (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of year	$ 4,584	$ 4,392
Net balance, beginning of year	4,584
Less claims paid during the year on claims incurred during:
Net balance, end of year	4,659	4,584
Total liability for unpaid policy claims	4,659	4,584	$ 4,392
Health insurance
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of year	3,952	3,884	3,707
Less reinsurance recoverables	27	30	27
Net balance, beginning of year	3,925	3,854	3,680
Add claims incurred during the year related to:
Current year	7,216	7,101	6,979
Prior years	(552)	(563)	(518)
Total incurred	6,664	6,538	6,461
Less claims paid during the year on claims incurred during:
Current year	4,715	4,612	4,530
Prior years	1,965	1,898	1,822
Total paid	6,680	6,510	6,352
Effect of foreign exchange rate changes on unpaid claims	29	43	65
Net balance, end of year	3,938	3,925	3,854
Add reinsurance recoverables	30	27	30
Total liability for unpaid policy claims	3,968	3,952	3,884
Life insurance
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of year	632	508
Less claims paid during the year on claims incurred during:
Total liability for unpaid policy claims	$ 691	$ 632	$ 508