ASSETS AND LIABILITIES HELD FOR SALE - Net Assets Held For Sale (Details) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Current liabilities $ (406) $ (480)
Hospital Operations and other | Discontinued Operations, Held-for-sale    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Accounts receivable 74  
Other current assets 50  
Investments and other long-term assets 2  
Property and equipment 398  
Other intangible assets 8  
Goodwill 67  
Current liabilities (93)  
Long-term liabilities (313)  
Net assets held for sale $ 193