SEGMENT INFORMATION - Additional Information (Detail) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2016
USD ($)
|
Sep. 30, 2015
USD ($)
|
Sep. 30, 2016
USD ($)
Segment
|
Sep. 30, 2015
USD ($)
|
|
| Segment Reporting [Abstract] | ||||
| Number of reportable segments | Segment | 3 | |||
| Member co-share amounts and government subsidies | $ 3,600 | $ 3,300 | $ 9,700 | $ 8,800 |
| Depreciation and amortization classified as benefit expense | $ 31 | $ 23 | $ 85 | $ 68 |