CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) $ in Thousands		Total		Total Stockholders' Equity	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income	Treasury Stock	Noncontrolling Interests		Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Total Stockholders' Equity	Cumulative Effect, Period of Adoption, Adjustment Accumulated Deficit
Balance at the beginning of the period (in shares) at Dec. 31, 2019					43,635,893				(1,050,260)
Balance at the beginning of the period at Dec. 31, 2019		$ 3,332,988		$ 3,148,133	$ 437	$ 3,343,983	$ (46,385)	$ (29,372)	$ (120,530)	$ 184,855	[1]	$ (18)	$ (18)	$ (18)
Increase (Decrease) in Stockholders' Equity
Net income (loss) excluding a loss attributable to redeemable noncontrolling interest		(19,453)		(19,508)			(19,508)			55	[1]
Interest rate swaps		(26,393)	[2]	(26,393)				(26,393)
Share of investee's other comprehensive income	[3]	0
Reclassification of redeemable noncontrolling interest to temporary equity		(6,091)								(6,091)	[1]
Derecognition of 110 North Wacker	[4]	(165,509)		12,935			1	12,934		(178,444)	[1]
Issuance of common shares (in shares)					12,270,900
Issuance of common shares and offering cost		593,616		593,616	$ 123	593,493
Stock plan activity (in shares)					68,090				(2,875)
Stock plan activity		4,522		4,522	$ 1	4,697			$ (176)
Balance at the end of the period (in shares) at Sep. 30, 2020					55,974,883				(1,053,135)
Balance at the end of the period at Sep. 30, 2020		3,713,662		3,713,287	$ 561	3,942,173	(65,910)	(42,831)	$ (120,706)	375	[5]
Balance at the beginning of the period (in shares) at Jun. 30, 2020					55,981,559				(1,050,260)
Balance at the beginning of the period at Jun. 30, 2020		3,739,703		3,554,815	$ 561	3,941,516	(205,621)	(61,111)	$ (120,530)	184,888	[5]
Increase (Decrease) in Stockholders' Equity
Net income (loss) excluding a loss attributable to redeemable noncontrolling interest		139,732		139,710			139,710			22	[5]
Interest rate swaps		5,346	[2]	5,346				5,346
Share of investee's other comprehensive income	[3]	0
Reclassification of redeemable noncontrolling interest to temporary equity		(6,091)								(6,091)	[5]
Derecognition of 110 North Wacker	[6]	(165,509)		12,935			1	12,934		(178,444)	[5]
Issuance of common shares and offering cost		3		3		3
Stock plan activity (in shares)					(6,676)				(2,875)
Stock plan activity		478		478		654			$ (176)
Balance at the end of the period (in shares) at Sep. 30, 2020					55,974,883				(1,053,135)
Balance at the end of the period at Sep. 30, 2020		3,713,662		3,713,287	$ 561	3,942,173	(65,910)	(42,831)	$ (120,706)	375	[5]
Balance at the beginning of the period (in shares) at Dec. 31, 2020					56,042,814				(1,070,558)
Balance at the beginning of the period at Dec. 31, 2020		3,715,023		3,714,603	$ 562	3,947,278	(72,556)	(38,590)	$ (122,091)	420	[1]
Increase (Decrease) in Stockholders' Equity
Net income (loss) excluding a loss attributable to redeemable noncontrolling interest		(58,129)		(57,700)			(57,700)			(429)	[1]
Interest rate swaps		11,232	[2]	11,232				11,232
Share of investee's other comprehensive income		4,083	[3]	4,083				4,083
Issuance of common shares and offering cost		(5)		(5)		(5)
Stock plan activity (in shares)					154,004				(1,774)
Stock plan activity		10,380		10,380	$ 1	10,541			$ (162)
Balance at the end of the period (in shares) at Sep. 30, 2021					56,196,818				(1,072,332)
Balance at the end of the period at Sep. 30, 2021		3,682,584		3,682,593	$ 563	3,957,814	(130,256)	(23,275)	$ (122,253)	(9)	[1]
Balance at the beginning of the period (in shares) at Jun. 30, 2021					56,196,818				(1,070,558)
Balance at the beginning of the period at Jun. 30, 2021		3,671,903		3,671,571	$ 563	3,955,162	(134,309)	(27,754)	$ (122,091)	332	[5]
Increase (Decrease) in Stockholders' Equity
Net income (loss) excluding a loss attributable to redeemable noncontrolling interest		3,712		4,053			4,053			(341)
Interest rate swaps		2,971	[2]	2,971				2,971
Share of investee's other comprehensive income		1,508	[3]	1,508				1,508
Stock plan activity (in shares)									(1,774)
Stock plan activity		2,490		2,490		2,652			$ (162)
Balance at the end of the period (in shares) at Sep. 30, 2021					56,196,818				(1,072,332)
Balance at the end of the period at Sep. 30, 2021		$ 3,682,584		$ 3,682,593	$ 563	$ 3,957,814	$ (130,256)	$ (23,275)	$ (122,253)	$ (9)	[1]

[1] Excludes redeemable noncontrolling interest, which is reflected in temporary equity. See Note 2 - Real Estate and Other Affiliates.

[2] Amounts are shown net of deferred tax expense of $0.8 million for the three months ended September 30, 2021, $1.2 million for the three months ended September 30, 2020, $3.1 million for the nine months ended September 30, 2021, and deferred tax benefit of $6.2 million for the nine months ended September 30, 2020.

[3] The amount for 2021 is shown net of deferred tax expense of $0.4 million for the three months ended September 30, 2021, and $1.2 million for the nine months ended September 30, 2021.

[4] Related to deconsolidation of 110 North Wacker. See Note 2 - Real Estate and Other Affiliates for additional information.

[5] Excludes redeemable noncontrolling interest, which is reflected in temporary equity. See Note 2 - Real Estate and Other Affiliates.

[6] Related to deconsolidation of 110 North Wacker. See Note 2 - Real Estate and Other Affiliates for additional information.