Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Summary of Change in Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 622,442
Net income (loss)	$ (5,237)	$ (2,270)	(2,301)	$ (6,430)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0	0	0	0
Other comprehensive loss - unrealized loss on valuation of swap agreements	(22,652)	2,950	(35,958)	8,603
Reclassification of realized interest on swap agreements	(535)	109	(1,086)	472
Noncontrolling interest contributions		6,550	32,191	6,550
Noncontrolling interest distributions	(1,645)	(14,945)	(4,882)	(15,640)
Employee Long-term Incentive Plan Unit Awards	1,988	2,301	5,442	6,113
Reallocation of noncontrolling interests	0	0	0	0
Ending Balance	618,910		618,910
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	640,421	639,998	622,442	648,440
Distributions declared of $0.28, 0.27 and $0.56, $0.54 per Common OP Unit for three and six months ended June 30, 2019 and 2018, respectively	(1,776)	(1,713)	(3,557)	(3,434)
Net income (loss)	(14,317)	(9,935)	(23,578)	(21,514)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	(557)	(481)	(3,510)	(1,123)
Other comprehensive loss - unrealized loss on valuation of swap agreements	(4,591)	198	(6,890)	1,358
Reclassification of realized interest on swap agreements	(47)	99	(68)	193
Noncontrolling interest contributions		6,550	32,191	6,550
Noncontrolling interest distributions	(1,645)	(14,945)	(4,882)	(15,640)
Employee Long-term Incentive Plan Unit Awards	1,835	2,126	5,195	5,842
Reallocation of noncontrolling interests	(413)	(2,023)	1,567	(798)
Ending Balance	618,910	619,874	618,910	619,874
Noncontrolling Interests | Restatement Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	1,567		1,567
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	535,377	533,603	518,219	545,519
Distributions declared of $0.28, 0.27 and $0.56, $0.54 per Common OP Unit for three and six months ended June 30, 2019 and 2018, respectively	0	0	0	0
Net income (loss)	(15,039)	(10,568)	(25,231)	(22,759)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0		0	0
Other comprehensive loss - unrealized loss on valuation of swap agreements	(3,464)	44	(5,068)	930
Reclassification of realized interest on swap agreements	(24)	90	(24)	174
Noncontrolling interest contributions		6,550	32,191	6,550
Noncontrolling interest distributions	(1,645)	(14,945)	(4,882)	(15,640)
Employee Long-term Incentive Plan Unit Awards	0	0	0	0
Reallocation of noncontrolling interests	0	0	0	0
Ending Balance	515,205	514,774	515,205	514,774
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates | Restatement Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	0		0
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	105,044	106,395	104,223	102,921
Distributions declared of $0.28, 0.27 and $0.56, $0.54 per Common OP Unit for three and six months ended June 30, 2019 and 2018, respectively	(1,776)	(1,713)	(3,557)	(3,434)
Net income (loss)	722	633	1,653	1,245
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	(557)	(481)	(3,510)	(1,123)
Other comprehensive loss - unrealized loss on valuation of swap agreements	(1,127)	154	(1,822)	428
Reclassification of realized interest on swap agreements	(23)	9	(44)	19
Noncontrolling interest contributions		0	0	0
Noncontrolling interest distributions	0	0	0	0
Employee Long-term Incentive Plan Unit Awards	1,835	2,126	5,195	5,842
Reallocation of noncontrolling interests	(413)	(2,023)	1,567	(798)
Ending Balance	103,705	$ 105,100	103,705	$ 105,100
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member | Restatement Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	$ 1,567		$ 1,567