Investments in Unconsolidated Real Estate Ventures - Financial Information - Table (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Schedule of Equity Method Investments
Gain (loss) on sale of real estate	$ 11,290		$ 11,290	$ 59,477
Combined balance sheet information:
Real estate, net	4,689,227		4,689,227		$ 4,767,941
Other assets, net	282,356		282,356		286,575
TOTAL ASSETS	6,008,211		6,008,211		6,079,547
Mortgages payable, net	1,591,143		1,591,143		1,593,738
Other liabilities, net	201,556		201,556		247,774
Total liabilities	2,290,331		2,290,331		2,342,593
Total equity	3,156,701		3,156,701		3,206,039
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY	6,008,211		6,008,211		6,079,547
Combined income statement information:
Revenues	154,644	$ 144,952	319,933	303,059
Net income (loss)	(3,318)	(40,263)	(27,387)	7,912
Investments in Unconsolidated Real Estate Ventures
Combined balance sheet information:
Real estate, net	2,262,453		2,262,453		2,247,384
Other assets, net	270,462		270,462		270,516
TOTAL ASSETS	2,532,915		2,532,915		2,517,900
Mortgages payable, net	1,149,589		1,149,589		1,179,188
Other liabilities, net	132,066		132,066		140,304
Total liabilities	1,281,655		1,281,655		1,319,492
Total equity	1,251,260		1,251,260		1,198,408
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY	2,532,915		2,532,915		$ 2,517,900
Combined income statement information:
Revenues	47,864	45,314	96,081	114,893
Operating income (loss)	41,493	(25,232)	43,207	(25,714)
Net income (loss)	33,356	(35,901)	26,830	(54,066)
Landmark Venture Partner | Landmark
Schedule of Equity Method Investments
Gain (loss) on sale of real estate		$ (16,400)		$ (16,400)
Landmark And CBREI Venture Partners | Landmark and CBREI
Schedule of Equity Method Investments
Gain (loss) on sale of real estate	$ 38,100		$ 38,100