Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Summary of Change in Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				$ 622,442					$ 622,442
Net income (loss)	$ 14,665	$ 8,840	$ (5,237)	2,936	$ (6,671)	$ (2,597)	$ (2,270)	$ (4,160)	21,204	$ (15,698)	$ 64,308
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									(35,674)	(2,659)	634
Reclassification of realized interest on swap agreements									(872)	71	3,317
Noncontrolling interest contributions									161,628	47,560	85,206
Noncontrolling interest distributions									(94,289)	(24,793)	(32,805)
Employee Long-term Incentive Plan Unit Awards									10,957	12,948	11,155
Reallocation of noncontrolling interests									0	0	0
Ending Balance	644,657				622,442				644,657	622,442
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				622,442				648,440	622,442	648,440	589,548
Distributions declared of $1.13,1.09 and $1.05 per Common OP Unit for year ended 2019,2018 and 2017, respectively									(7,124)	(6,888)	(6,453)
Net income (loss)									(31,841)	(47,137)	2,838
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership									(5,104)	(2,068)	(1,541)
Other comprehensive loss - unrealized loss on valuation of swap agreements									(4,935)	(810)	(147)
Reclassification of realized interest on swap agreements									80	320	686
Noncontrolling interest contributions									161,628	47,560	85,206
Noncontrolling interest distributions									(94,289)	(24,793)	(32,805)
Employee Long-term Incentive Plan Unit Awards									10,411	12,374	10,457
Reallocation of noncontrolling interests									(6,611)	(4,556)	651
Ending Balance	644,657				622,442				644,657	622,442	648,440
Noncontrolling Interests | Restatement Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	(6,611)								(6,611)
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				518,219				545,519	518,219	545,519	494,126
Distributions declared of $1.13,1.09 and $1.05 per Common OP Unit for year ended 2019,2018 and 2017, respectively									0	0	0
Net income (loss)									(35,677)	(49,709)	(1,321)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership									0		0
Other comprehensive loss - unrealized loss on valuation of swap agreements									(3,036)	(681)	(232)
Reclassification of realized interest on swap agreements									142	323	545
Noncontrolling interest contributions									161,628	47,560	85,206
Noncontrolling interest distributions									(94,289)	(24,793)	(32,805)
Employee Long-term Incentive Plan Unit Awards									0	0	0
Reallocation of noncontrolling interests									0	0	0
Ending Balance	546,987				518,219				546,987	518,219	545,519
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				$ 104,223				$ 102,921	104,223	102,921	95,422
Distributions declared of $1.13,1.09 and $1.05 per Common OP Unit for year ended 2019,2018 and 2017, respectively									(7,124)	(6,888)	(6,453)
Net income (loss)									3,836	2,572	4,159
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership									(5,104)	(2,068)	(1,541)
Other comprehensive loss - unrealized loss on valuation of swap agreements									(1,899)	(129)	85
Reclassification of realized interest on swap agreements									(62)	(3)	141
Noncontrolling interest contributions									0	0	0
Noncontrolling interest distributions									0	0	0
Employee Long-term Incentive Plan Unit Awards									10,411	12,374	10,457
Reallocation of noncontrolling interests									(6,611)	(4,556)	651
Ending Balance	97,670				$ 104,223				97,670	$ 104,223	$ 102,921
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member | Restatement Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance	$ (6,611)								$ (6,611)