Consolidated Statements of Changes In Equity - USD ($) $ in Thousands	Total	Previously Reported	Cumulative Effect, Period Of Adoption, Adjustment	Cumulative Effect, Period Of Adoption, Adjustment Revision of Prior Period, Change in Accounting Principle, Adjustment	Common Stock	Common Stock Previously Reported	Paid-in Capital	Paid-in Capital Previously Reported	Redeemable Perpetual Preferred Stock	Redeemable Perpetual Preferred Stock Previously Reported	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Previously Reported	Distributions in Excess of Accumulated Earnings Cumulative Effect, Period Of Adoption, Adjustment Revision of Prior Period, Change in Accounting Principle, Adjustment	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Previously Reported	Non-controlling interests – Common OP Units	Non-controlling interests – Common OP Units Previously Reported
Beginning balance at Dec. 31, 2018	$ 1,193,344				$ 1,792		$ 1,328,495		$ 0		$ (211,034)			$ 2,299		$ 71,792
Increase (Decrease) in Stockholders' Equity
Exchange of Common OP Units for Common Stock	0						66									(66)
Issuance of Common Stock through exercise of options	53						53
Issuance of Common Stock through employee stock purchase plan	652						652
Compensation expenses related to restricted stock and stock options	2,420						2,420
Repurchase of Common Stock or Common OP Units	(53)						(53)
Adjustment for Common OP Unitholders in the Operating Partnership	0						(56)									56
Adjustment for fair market value of swap	(931)													(931)
Consolidated net income	120,535										113,309					7,226
Distributions	(58,639)										(55,123)					(3,516)
Other	(63)						(63)
Ending balance at Mar. 31, 2019	1,257,318				1,792		1,331,514		0		(152,848)			1,368		75,492
Beginning balance at Dec. 31, 2018	$ 1,193,344				1,792		1,328,495		0		(211,034)			2,299		71,792
Increase (Decrease) in Stockholders' Equity
Exchange of Common OP units for common stock (in shares)	990,650
Adjustment for fair market value of swap	$ (2,541)
Ending balance at Jun. 30, 2019	1,307,474				1,812		1,396,707		0		(162,204)			(242)		71,401
Beginning balance at Mar. 31, 2019	1,257,318				$ 1,792		1,331,514		0		(152,848)			1,368		75,492
Increase (Decrease) in Stockholders' Equity
Exchange of Common OP units for common stock (in shares)					10,000
Exchange of Common OP Units for Common Stock	0						6,425									(6,435)
Issuance of Common Stock through employee stock purchase plan	587						587
Issuance of common stock through our ATM equity offering program (in shares)					10,000
Issuance of Common Stock through our ATM equity offering program	59,319						59,309
Compensation expenses related to restricted stock and stock options	2,625						2,625
Adjustment for Common OP Unitholders in the Operating Partnership	0						(2,883)									2,883
Adjustment for fair market value of swap	(1,610)													(1,610)
Consolidated net income	49,085								8		46,401					2,676
Distributions	(58,980)								(8)		(55,757)			0		(3,215)
Other	(870)						(870)
Ending balance at Jun. 30, 2019	1,307,474				$ 1,812		1,396,707		0		(162,204)			(242)		71,401
Beginning balance at Dec. 31, 2019	$ 1,318,013	$ 1,321,888	$ 3,900		1,812	$ 1,812	1,402,696	$ 1,402,696			(158,193)	$ (154,318)		(380)	$ (380)	72,078	$ 72,078
Beginning balance (ASU 2016-13) at Dec. 31, 2019				$ (3,875)									$ (3,875)
Increase (Decrease) in Stockholders' Equity
Exchange of Common OP units for common stock (in shares)	9,228
Adjustment for fair market value of swap	$ (781)
Consolidated net income	48,853															2,658
Ending balance at Jun. 30, 2020	1,307,383				1,812		1,405,764		0	$ 0	(169,903)			(1,161)		70,871
Beginning balance at Mar. 31, 2020	1,320,907				1,812		1,402,514		0		(153,703)			(1,713)		71,997
Increase (Decrease) in Stockholders' Equity
Issuance of Common Stock through employee stock purchase plan	531						531
Compensation expenses related to restricted stock and stock options	2,669						2,669
Adjustment for Common OP Unitholders in the Operating Partnership	0						193									(193)
Adjustment for fair market value of swap	552													552
Consolidated net income	0								8		0					46,187
Distributions	(65,986)								(8)		(62,387)					(3,591)
Other	(143)						(143)
Ending balance at Jun. 30, 2020	$ 1,307,383				$ 1,812		$ 1,405,764		$ 0	$ 0	$ (169,903)			$ (1,161)		$ 70,871