Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2017	Dec. 31, 2020	Dec. 31, 2019
Federal Income Tax Reporting
Maximum ownership as a percentage of the voting power or value of the securities of each issuer other than REIT or "TRS"			10.00%
Maximum ownership of securities in all TRS (as a percent)			20.00%		25.00%
Maximum ownership of securities in all TRS when considered together with other non-real estate assets (as a percent)			25.00%
Gross amount of NOL of TRS						$ 4,600,000	$ 4,400,000
Net operating losses
Gross amount of NOLs available to company	$ 13,000,000.0		$ 13,000,000.0
Income Tax Expense
Revised Texas Franchise Tax			123,000	$ 132,000
Tax expense	$ 56,000	$ 64,000	123,000	$ 132,000
Deferred income taxes			$ 0