Debt - Components of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Line of Credit Facility [Line Items]
Amortization of deferred financing costs	$ 237	$ 317	$ 505	$ 612
Interest Expense	1,995	2,316	4,218	4,561
Subordinated debt
Line of Credit Facility [Line Items]
Interest incurred	0	6	4	7
Note Payable—Verde Notes
Line of Credit Facility [Line Items]
Interest incurred	89	363	230	690
Working Capital Facility
Line of Credit Facility [Line Items]
Letters of credit fees and commitment fees	490	422	858	780
Working Capital Facility | Senior Credit Facility
Line of Credit Facility [Line Items]
Interest incurred	$ 1,179	$ 1,208	$ 2,621	$ 2,472