Quarterly report pursuant to Section 13 or 15(d)

Additional Cash Flow Information (Details)

v3.10.0.1
Additional Cash Flow Information (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]        
Property, plant and equipment non-cash accruals $ 3,529 $ 0    
Accrued term loan issuance costs 441 0    
Non-cash settlement of withholding taxes associated with the 2017 bonus accrual and vesting of certain awards 5,733 828    
Non-cash settlement of the 2017 bonus accrual 15,202 0    
Cash and cash equivalents 172,317 138,023 $ 128,273  
Non-current restricted cash 57,440 0 0  
Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 229,757 $ 138,023 $ 128,273 $ 21,398