CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Allowance on receivables	$ 782	$ 835
Allowance on accrued rental income	4,587	6,947
Debt costs, accumulated amortization	$ 19,377	$ 17,294
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	15,000,000	15,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	375,000,000	375,000,000
Common stock, shares issued (in shares)	175,635,792	175,232,971
Common stock, shares outstanding (in shares)	175,635,792	175,232,971
Series F Preferred Stock
Dividend rate	5.20%
Preferred stock, issued (in shares)	138,000	138,000
Preferred stock, outstanding (in shares)	138,000	138,000
Preferred stock, stated liquidation value per share (in dollars per share)	$ 2.500	$ 2.500