EXPENSES ASSOCIATED WITH LONG-DURATION INSURANCE PRODUCTS - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Long Duration Insurance Products [Line Items]
Percent of consolidated premiums and services revenues related to long-duration insurance products		1.00%
Future policy benefits payable	$ 2,834,000,000	$ 2,923,000,000	$ 2,834,000,000
Long-term insurance reserve strengthening expense	505,000,000
Benefit expense with future policy benefits payable		(22,000,000)	439,000,000	$ (80,000,000)
Amortization of deferred acquisition costs		71,000,000	67,000,000	63,000,000
Adjustment to future policy benefits assuming unrealized gains on investments realized and reinvested at current yields		168,000,000	77,000,000
Increase in future policy benefits payable	659,000,000		659,000,000
Increase in reinsurance recoverable	154,000,000		154,000,000
Premium deficiency reserve	0	0	0	$ 176,000,000	$ 0
Deferred acquisition costs associated with our individual major medical policies	16,000,000	3,000,000	16,000,000
100% Coinsurance Agreements
Long Duration Insurance Products [Line Items]
Future policy benefits payable	201,000,000	$ 199,000,000	201,000,000
Percentage of coinsurance agreement		100.00%
Closed Block Long Term Care Policies
Long Duration Insurance Products [Line Items]
Future policy benefits payable	2,200,000,000	$ 2,300,000,000	2,200,000,000
Individual Major Medical Policies
Long Duration Insurance Products [Line Items]
Future policy benefits payable	$ 86,000,000	$ 19,000,000	$ 86,000,000