Loan Facilities - Schedule of Short-term Debt (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Short-term principal and commitment fee	$ 73,500	$ 73,500
Exit fee payable	1,500	1,500
Accrued unpaid interest	2,386	892
Unamortized debt issuance costs	(220)	(1,054)
Debt discount	(242)	(1,161)
Repayment of short-term principal, including exit fee	(2,996)
Total short-term debt	73,928	73,677
New Money Loans
Debt Instrument [Line Items]
Short-term principal and commitment fee	51,000	51,000
Exit fee payable	1,500	1,500
Accrued unpaid interest	2,207	826
Unamortized debt issuance costs	(220)	(1,054)
Debt discount	(242)	(1,161)
Repayment of short-term principal, including exit fee	(2,996)
Total short-term debt	51,249	51,111
Roll Up Loans
Debt Instrument [Line Items]
Short-term principal and commitment fee	22,500	22,500
Exit fee payable	0	0
Accrued unpaid interest	179	66
Unamortized debt issuance costs	0	0
Debt discount	0	0
Repayment of short-term principal, including exit fee	0
Total short-term debt	$ 22,679	$ 22,566