Supplemental Financial Statement Information - Cash flow, etc. (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Supplemental Cash Flow Information
Increase in accounts payable and accrued liabilities related to additions to real estate assets			$ 8,767	$ 515
Interest paid
Interest payments	$ 1,699	$ 1,762	3,390	3,446
Interest capitalized included in interest payments	$ 223	33	$ 345	33
Income tax rate
Income tax benefit		$ 174		$ 259
Income tax benefit rate (as a percent)				20.90%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent				21.00%