ASSETS AND LIABILITIES HELD FOR SALE (Details)
$ in Millions
3 Months Ended
Mar. 31, 2018
USD ($)
hospital
Dec. 31, 2017
USD ($)
hospital
Sep. 30, 2017
USD ($)
hospital
Mar. 31, 2017
USD ($)
Current Assets and Liabilities Held for Sale        
Number of hospitals | hospital 69      
Impairment charges       $ 1.0
Proceeds from sales of facilities and other assets $ 425.0     $ 20.0
Saint Louis University Hospital | Disposal Group, Held-for-sale, Not Discontinued Operations        
Current Assets and Liabilities Held for Sale        
Assets held for sale   $ 45.0    
Liabilities held for sale 3.0      
Chicago Facilities | Disposal Group, Held-for-sale, Not Discontinued Operations        
Current Assets and Liabilities Held for Sale        
Assets held for sale   $ 113.0    
Liabilities held for sale 50.0      
Number of hospitals | hospital   3    
Impairment charges 17.0 $ 73.0    
Chicago Facilities | Discontinued Operations, Held-for-sale        
Current Assets and Liabilities Held for Sale        
Impairment charges 17.0      
Philadelphia Facilities | Disposal Group, Held-for-sale, Not Discontinued Operations        
Current Assets and Liabilities Held for Sale        
Proceeds from sales of facilities and other assets 152.5      
Notes Issued 17.5      
Philadelphia Facilities | Discontinued Operations, Held-for-sale        
Current Assets and Liabilities Held for Sale        
Impairment charges     $ 235.0  
United Kingdom Facilities | Discontinued Operations, Held-for-sale        
Current Assets and Liabilities Held for Sale        
Assets held for sale 430.0      
Liabilities held for sale 341.0      
Number of hospitals | hospital     9  
Impairment charges     $ 59.0  
California Facilities | Disposal Group, Held-for-sale, Not Discontinued Operations        
Current Assets and Liabilities Held for Sale        
Assets held for sale 11.0      
Liabilities held for sale 12.0      
MacNeal Hospital | Disposal Group, Disposed of by Sale, Not Discontinued Operations        
Current Assets and Liabilities Held for Sale        
Proceeds from sales of facilities and other assets 249.0      
Gain on sale of business 98.0      
Abrazo Maryvale Hospital | Disposal Group, Disposed of by Sale, Not Discontinued Operations        
Current Assets and Liabilities Held for Sale        
Proceeds from sales of facilities and other assets $ 7.0