Segment Information - Schedule of Reconciliation of Net Income Attributable to Parent (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Net income (loss) attributable to common shareholders	$ 24,861,000	$ (4,190,000)
Depreciation and amortization	48,719,000	49,160,000
Corporate and other	12,314,000	8,414,000
Third-party real estate services	28,066,000	22,609,000
Share-based compensation related to Formation Transaction and special equity awards	11,131,000	9,428,000
Transaction and other costs	4,895,000	4,221,000
Interest expense	17,174,000	19,257,000
Income tax benefit	(1,172,000)	(908,000)
Net (income) loss attributable to redeemable noncontrolling interests	3,387,000	(594,000)
Third-party real estate services, including reimbursements	27,691,000	24,330,000
Other Income, Excluding Parking Income	1,640,000	1,116,000
Income (loss) from unconsolidated real estate ventures, net	3,601,000	(1,902,000)
Interest and other income, net	951,000	573,000
Gain on sale of real estate	39,033,000	455,000
Net loss attributable to noncontrolling interests	0	2,000
Consolidated NOI	76,459,000	82,823,000
Parking Income	$ 6,455	$ 6,363