Restatement of Previously Issued Financial Statements - Condensed Consolidated Statement of Stockholders' Equity (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total stockholders' equity	$ 165,158	$ 203,690
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total stockholders' equity	179,516
Correction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total stockholders' equity	(14,358)
Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total stockholders' equity	(151,966)	$ (113,836)
Accumulated Deficit | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total stockholders' equity	(137,608)
Accumulated Deficit | Correction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total stockholders' equity	$ (14,358)