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Property and Equipment - Additional Disclosures (Details)
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2018
USD ($)
Mar. 31, 2017
USD ($)
item
Dec. 31, 2017
USD ($)
Property and Equipment      
Depreciation expense $ 24.3 $ 23.3  
Gain on disposition of units 0.3 $ 0.2  
Insurance Recoveries 0.6    
Number Of Compressor Units That Are To Be Retired Or Sold Or Reutilized | item   2  
Accounts payable and accrued liabilities      
Property and Equipment      
Purchases of property and equipment $ 25.6   $ 10.8