Segments - Schedule of Reconciliation of NOI to Net Loss Attributable to Common Stockholders (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting [Abstract]
NOI	[1]	$ 122,553	$ 113,119	$ 240,757	$ 239,364
Fee income		6,201	6,209	12,871	12,539
Depreciation and amortization expense		(59,925)	(58,716)	(118,230)	(117,143)
General and administrative expenses		(18,418)	(17,901)	(32,782)	(30,150)
NOI from unconsolidated joint ventures		(10,557)	(10,376)	(20,883)	(23,768)
Loss from unconsolidated joint ventures		(15,717)	(5,955)	(21,033)	(10,176)
Interest and other income, net		1,070	2,252	2,372	1,256
Interest and debt expense		(34,914)	(36,009)	(69,653)	(72,628)
Adjustments related to discontinued operations			(2,147)		(4,358)
Other, net		13	(169)	(88)	(320)
Loss from continuing operations, before income taxes		(9,694)	(9,693)	(6,669)	(5,384)
Income tax expense		(434)	(138)	(1,575)	(742)
Loss from continuing operations, net		(10,128)	(9,831)	(8,244)	(6,126)
Income from discontinued operations, net			2,147		3,668
Net loss		(10,128)	(7,684)	(8,244)	(2,458)
Consolidated joint ventures		(7,428)	(405)	(13,156)	(1,919)
Consolidated real estate fund		29	1,235	(56)	1,212
Operating Partnership		1,584	584	1,935	243
Net loss attributable to common stockholders		$ (15,943)	$ (6,270)	$ (19,521)	$ (2,922)

[1] NOI is used to measure the operating performance of our properties. NOI consists of rental revenue (which includes property rentals, tenant reimbursements and lease termination income) and certain other property-related revenue less operating expenses (which includes property-related expenses such as cleaning, security, repairs and maintenance, utilities, property administration and real estate taxes). We use NOI internally as a performance measure and believe it provides useful information to investors regarding our financial condition and results of operations because it reflects only those income and expense items that are incurred at the property level. Other real estate companies may use different methodologies for calculating NOI and, accordingly, our presentation of NOI may not be comparable to other real estate companies.