Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Summary of Change in Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 644,657
Net (loss) income	$ (38,289)	$ 8,840	(33,422)	$ 6,539
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership		0	0	0
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	952	(15,388)	(82,444)	(51,347)
Acquisition of noncontrolling interest			588
Reclassification of realized interest on swap agreements	5,506	(288)	9,598	(1,374)
Noncontrolling interest contributions	8,427	129,438	36,736	161,628
Noncontrolling interest distributions	(20,117)	(29,713)	(24,654)	(34,595)
Employee Long-term Incentive Plan Unit Awards	2,413	1,916	8,551	7,361
Reallocation of noncontrolling interests	0	0	0	0
Ending Balance	598,870		598,870
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	637,739	618,910	644,657	622,442
Distributions declared per Common OP Unit		(1,765)	(2,095)	(5,322)
Distributions on Preferred OP Units	(123)
Net (loss) income	(29,259)	(1,618)	(35,388)	(25,196)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership		(720)	(6,544)	(4,230)
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	17	(1,115)	(21,691)	(8,006)
Cumulative effect of change in accounting principle (Note 1)			(11)
Acquisition of noncontrolling interest			588
Reclassification of realized interest on swap agreements	2,105	7	3,543	(61)
Noncontrolling interest contributions	8,427	129,438	36,736	161,628
Noncontrolling interest distributions	(20,117)	(29,713)	(24,654)	(34,595)
Employee Long-term Incentive Plan Unit Awards	2,181	1,768	7,973	6,965
Reallocation of noncontrolling interests	(2,100)	(5,251)	(4,244)	(3,684)
Ending Balance	598,870	709,941	598,870	709,941
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	547,418	515,205	546,987	518,219
Distributions declared per Common OP Unit		0	0	0
Distributions on Preferred OP Units	0
Net (loss) income	(28,907)	(2,403)	(35,958)	(27,633)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership		0	0	0
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	(166)	(251)	(18,423)	(5,320)
Cumulative effect of change in accounting principle (Note 1)			(11)
Acquisition of noncontrolling interest			588
Reclassification of realized interest on swap agreements	2,042	23	3,432
Noncontrolling interest contributions	8,427	129,438	36,736	161,628
Noncontrolling interest distributions	(20,117)	(29,713)	(24,654)	(34,595)
Employee Long-term Incentive Plan Unit Awards	0	0	0	0
Reallocation of noncontrolling interests	0	0	0	0
Ending Balance	508,697	612,299	508,697	612,299
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	90,321	103,705	97,670	104,223
Distributions declared per Common OP Unit		(1,765)	(2,095)	(5,322)
Distributions on Preferred OP Units	(123)
Net (loss) income	(352)	785	570	2,437
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership		(720)	(6,544)	(4,230)
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	183	(864)	(3,268)	(2,686)
Reclassification of realized interest on swap agreements	63	(16)	111	(61)
Noncontrolling interest contributions	0	0	0	0
Noncontrolling interest distributions	0	0	0	0
Employee Long-term Incentive Plan Unit Awards	2,181	1,768	7,973	6,965
Reallocation of noncontrolling interests	(2,100)	(5,251)	(4,244)	(3,684)
Ending Balance	$ 90,173	$ 97,642	$ 90,173	$ 97,642