SEGMENT INFORMATION - General Information and Customer Concentration (Details)
3 Months Ended 12 Months Ended
Mar. 31, 2018
hospital
state
Dec. 31, 2017
hospital
Segment Reporting Information [Line Items]    
Number of surgical hospitals 21  
Conifer    
Segment Reporting Information [Line Items]    
Ownership percentage by parent 76.20%  
Minimum | Conifer    
Segment Reporting Information [Line Items]    
Number of hospitals to which segment of the entity provides revenue cycle services 800  
United Surgical Partners International    
Segment Reporting Information [Line Items]    
Number of ambulatory surgery centers 251  
Number of urgent care centers 34  
Number of diagnostic imaging centers 23  
Number of states where operations occur | state 27  
Ownership percentage by parent 80.00%  
European Surgical Partners Ltd    
Segment Reporting Information [Line Items]    
Number of facilities owned by subsidiaries 9 9