Consolidated Statement of Equity - USD ($) $ in Thousands	Total	Par Value	Additional Paid in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Total Shareholders’ Equity	Operating Partnership Noncontrolling Interest	Partially Owned Properties Noncontrolling Interest	Total Noncontrolling Interests
Balance at Dec. 31, 2018	$ 2,447,660	$ 1,824	$ 2,791,555	$ (428,307)	$ 14,433	$ 2,379,505	$ 67,477	$ 678	$ 68,155
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from sale of common shares	31,020	17	31,003			31,020
Restricted share award grants, net	355	2	640	(287)		355
Purchase of OP Units	(105)						(105)		(105)
Dividends/distributions declared	(43,694)			(42,536)		(42,536)	(1,158)		(1,158)
Preferred distributions	(284)			(284)		(284)
Distributions	(47)							(47)	(47)
Change in market value of Redeemable Noncontrolling Interest	(290)		(290)	0		(290)
Adjustment for Noncontrolling Interests ownership in Operating Partnership	(3,476)				(3,476)	(3,476)
Net income	11,426			11,057		11,057	305	64	369
Adjustment for Noncontrolling Interests ownership in Operating Partnership	0		(149)			(149)	149		149
Balance at Mar. 31, 2019	2,442,326	1,843	2,822,520	(460,357)	10,957	2,374,963	66,668	695	67,363
Balance at Dec. 31, 2019	2,480,984	1,900	2,931,921	(529,194)	4,321	2,408,948	71,697	339	72,036
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from sale of common shares	239,232	124	239,108			239,232
Restricted share award grants, net	(201)	2	245	(448)		(201)
Purchase of OP Units	(93)						(93)		(93)
Dividends/distributions declared	(47,911)			(46,636)		(46,636)	(1,275)		(1,275)
Preferred distributions	(317)			(317)		(317)
Distributions	(41)							(41)	(41)
Change in market value of Redeemable Noncontrolling Interest	(980)		581	(1,561)		(980)
Adjustment for Noncontrolling Interests ownership in Operating Partnership	(9,986)				(9,986)	(9,986)
Net income	14,885			14,414		14,414	404	67	471
Adjustment for Noncontrolling Interests ownership in Operating Partnership	0		(2,038)			(2,038)	2,038		2,038
Balance at Mar. 31, 2020	$ 2,675,425	$ 2,026	$ 3,169,670	$ (563,742)	$ (5,665)	$ 2,602,289	$ 72,771	$ 365	$ 73,136