BASIS OF PRESENTATION - Investments in Unconsolidated Affiliates (Details) $ in Millions |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2018
USD ($)
hospital
center
|
Mar. 31, 2017
USD ($)
|
|
| Schedule of Equity Method Investments [Line Items] | ||
| Number of outpatient centers | center | 460 | |
| Gain on sale of equity investments | $ | $ 13 | |
| Investee results reflected | 1 | |
| Net operating revenues | $ | $ 574 | $ 584 |
| Net income | $ | 116 | 115 |
| Net income attributable to the investees | $ | $ 71 | $ 76 |
| Ambulatory Care | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Number of outpatient centers recorded not using equity method | hospital | 230 | |
| Number of outpatient centers recorded using equity method | hospital | 108 | |
| Number of outpatient centers | hospital | 338 | |
| Hospital Operations and other | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Number of hospitals recorded using equity method | hospital | 4 | |