Earnings Per Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted average nonvested restricted shares outstanding	400,000	400,000	500,000
Weighted average number of OP units outstanding	81,000	83,000	65,000
Market Performance-Based Equity Award [Member] | Chief Executive Officer [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares issuable under Stock incentive plan	0	0	0