GUARANTEES AND CONTINGENCIES (Detail) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2017 USD ($)	Sep. 30, 2017	Nov. 02, 2017 USD ($)	May 01, 2014 matter	Jan. 06, 2012 provider
Loss Contingencies [Line Items]
Number of medical providers questioned (one or more) | provider					1
Number of matters related to a Notice of Non-Intervention | matter				1
Subsequent Event
Loss Contingencies [Line Items]
Litigation recoveries sought			$ 611
TRICARE Contract
Loss Contingencies [Line Items]
Contract term, years		5 years
Total Medicare
Loss Contingencies [Line Items]
Percentage of premiums and services revenue		78.00%
Military services
Loss Contingencies [Line Items]
Percentage of premiums and services revenue		0.70%
Medicaid
Loss Contingencies [Line Items]
Percentage of premiums and services revenue		5.00%
Penn Treaty Insolvency | Insurance-related Assessments
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss	$ 54