Leases - Lease Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of right-of-use assets	$ 188
Interest on lease liabilities	76
Operating lease costs	981
Variable lease costs	86
Total lease costs	1,331
Solar Panel Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of right-of-use assets	188
Interest on lease liabilities	76
Total lease costs	264
Ground Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease costs	439
Variable lease costs	41
Total lease costs	480
Office, equipment, and vehicle leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease costs	542
Variable lease costs	45
Total lease costs	$ 587