Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of right-of-use assets	$ 187	$ 375
Interest on lease liabilities	74	150
Operating lease costs	985	1,966
Variable lease costs	64	150
Total lease costs	1,310	2,641
Solar Panel Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of right-of-use assets	187	375
Interest on lease liabilities	74	150
Total lease costs	261	525
Ground Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease costs	436	875
Variable lease costs	41	82
Total lease costs	477	957
Office, equipment, and vehicle leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease costs	549	1,091
Variable lease costs	23	68
Total lease costs	$ 572	$ 1,159