Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Summary of Change in Noncontrolling Interest (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				$ 607,239
Net income		$ 1,231	$ 64,906	3,091	$ 4,867
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership		0	0	0	0
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements		(10,073)	(8,621)	23,483	(83,395)
Reclassification of realized interest on swap agreements		5,324	3,115	10,641	4,092
Noncontrolling interest contributions		5,868	21,041	17,109	28,309
Noncontrolling interest distributions		(4,355)	(1,418)	(11,031)	(4,536)
Employee Long-term Incentive Plan Unit Awards		2,624	2,317	7,135	6,136
Noncontrolling interest gain		(2,687)	45,496	(5,989)	(6,129)
Reallocation of noncontrolling interests		0	0	0	0
Ending Balance		617,659		617,659
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		617,522	577,096	607,239	644,657
Distributions declared per Common OP Unit		1,052	123	(2,100)	(1,972)
Net income		(2,687)	45,496	(5,989)	(6,129)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership		(115)	(4,072)	(409)	(6,544)
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements		(663)	(2,179)	3,380	(21,708)
Reclassification of realized interest on swap agreements		1,861	1,167	(3,762)	(1,439)
Noncontrolling interest contributions		5,868	21,041	17,109	28,309
Noncontrolling interest distributions		(4,355)	(1,418)	(11,031)	(4,536)
Employee Long-term Incentive Plan Unit Awards		2,399	2,142	6,448	5,790
Noncontrolling interest gain			(588)		(588)
Reallocation of noncontrolling interests	[1]	(1,119)	(1,999)	(750)	(2,144)
Ending Balance		617,659	637,739	617,659	637,739
Noncontrolling Interests | Cumulative Effect of Change in Accounting Principle
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance			(11)		(11)
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	[2]	522,592	483,714	517,808	546,987
Distributions declared per Common OP Unit	[2]	0	0	0	0
Net income	[2]	(3,085)	44,237	(6,857)	(7,052)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	[2]	0	0	0	0
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	[2]	(257)	(1,869)	1,886	(18,257)
Reclassification of realized interest on swap agreements	[2]	1,808	1,125	(3,656)	(1,390)
Noncontrolling interest contributions	[2]	5,868	21,041	17,109	28,309
Noncontrolling interest distributions	[2]	(4,355)	(1,418)	(11,031)	(4,536)
Employee Long-term Incentive Plan Unit Awards	[2]	0	0	0	0
Noncontrolling interest gain	[2]		(588)		(588)
Reallocation of noncontrolling interests	[1],[2]	0	0	0	0
Ending Balance	[2]	522,571	547,418	522,571	547,418
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates | Cumulative Effect of Change in Accounting Principle
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	[2]		(11)		(11)
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	[3]	94,930	93,382	89,431	97,670
Distributions declared per Common OP Unit	[3]	1,052	123	(2,100)	(1,972)
Net income	[3]	398	1,259	868	923
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	[3]	(115)	(4,072)	(409)	(6,544)
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	[3]	(406)	(310)	1,494	(3,451)
Reclassification of realized interest on swap agreements	[3]	53	42	(106)	(49)
Noncontrolling interest contributions	[3]	0	0	0	0
Noncontrolling interest distributions	[3]	0	0	0	0
Employee Long-term Incentive Plan Unit Awards	[3]	2,399	2,142	6,448	5,790
Noncontrolling interest gain	[3]		0		0
Reallocation of noncontrolling interests	[1],[3]	(1,119)	(1,999)	(750)	(2,144)
Ending Balance	[3]	$ 95,088	90,321	$ 95,088	90,321
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member | Cumulative Effect of Change in Accounting Principle
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	[3]		$ 0		$ 0

[1] Adjustment reflects the difference between the fair value of the consideration received or paid and the book value of the Common Shares, Common OP Units, Preferred OP Units, and LTIP Units involving changes in ownership.

[2] Noncontrolling interests in partially-owned affiliates comprise third-party interests in Funds II, III, IV and V, and Mervyns II, and six other subsidiaries.

[3] Noncontrolling interests in the Operating Partnership are comprised of (i) the limited partners’ 3,101,958 Common OP Units at each of June 30, 2021 and 2020; (ii) 188 Series A Preferred OP Units at each of June 30, 2021 and 2020; (iii) 126,593 Series C Preferred OP Units at each of June 30, 2021 and 2020; and (iv) 3,434,894 and 2,886,207 LTIP units at June 30, 2021 and 2020, respectively, as discussed in Share Incentive Plan (Note 13). Distributions declared for Preferred OP Units are reflected in net income (loss) in the table above.