Fair Value Measurements (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, beginning of period	$ 1,669
New Accounting Pronouncement, Effect of Adoption, Quantification	(46)
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(259)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Instruments Classified in Shareholders' Equity, Transfers out of Level 3	(1,364)
Warrant liability, end of period	$ 0