Debt - Carrying Value of Debt Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jul. 31, 2016
Debt Instrument [Line Items]
Principal	$ 291,198	$ 284,340
Carrying Value	258,937	253,256
Fair Value	263,641	246,091
Bank loans
Debt Instrument [Line Items]
Principal	12,592	3,917
Carrying Value	11,674	3,917
Fair Value	14,902	3,829
Bank loans | PWSC Loan
Debt Instrument [Line Items]
Principal	2,717	3,917
Carrying Value	2,717	3,917
Fair Value	2,656	3,829
Bank loans | KWH Loan
Debt Instrument [Line Items]
Principal	9,875	0
Carrying Value	8,957	0
Fair Value	12,246	0
Note payable
Debt Instrument [Line Items]
Principal	188,106	189,923
Carrying Value	197,039	199,316
Fair Value	198,515	192,239
Note payable | Flower Note
Debt Instrument [Line Items]
Principal	7,555	7,768
Carrying Value	7,555	7,768
Fair Value	8,322	8,565
Note payable | Net Lease Note
Debt Instrument [Line Items]
Principal	9,000	9,000
Carrying Value	9,000	9,000
Fair Value	9,151	9,409
Mortgage
Debt Instrument [Line Items]
Principal	171,551	173,155
Carrying Value	180,484	182,548
Fair Value	181,042	174,265	$ 191,700
Subordinated debt
Debt Instrument [Line Items]
Principal	90,500	90,500
Carrying Value	50,224	50,023
Fair Value	$ 50,224	$ 50,023