Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Mar. 15, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability	$ 902	$ 900
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability	902
Convertible Notes | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of long-term debt	$ 209,600			$ 258,300
Secured Debt | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of long-term debt			$ 16,600