Investments in Unconsolidated Joint Ventures - Summary of Financial Information of Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Equity Method Investments [Line Items]
Real estate, net		$ 7,015,456		$ 7,015,456		$ 7,099,669
Cash and cash equivalents and restricted cash		546,907	$ 323,438	546,907	$ 323,438	331,487	$ 365,409
Intangible assets, net		167,675		167,675		203,169
Other assets		80,660		80,660		51,373
Total assets	[1]	8,806,494		8,806,494		8,734,135
Notes and mortgages payable, net		3,798,944		3,798,944		3,783,851
Intangible liabilities, net		61,485		61,485		73,789
Other liabilities		59,531		59,531		66,004
Total liabilities	[1]	4,253,361		4,253,361		4,103,173
Equity		3,690,246		3,690,246		3,785,730
Total liabilities and equity		8,806,494		8,806,494		8,734,135
Rental revenue		165,420	181,115	504,834	530,500
Fee and other income		11,355	10,138	27,045	26,485
Total revenues		176,775	191,253	531,879	556,985
Operating		67,865	68,846	199,192	199,043
Depreciation and amortization		58,889	60,696	176,032	181,685
Total expenses		143,640	146,647	422,721	433,889
Interest and other (loss) income, net		1,104	1,222	2,360	7,705
Interest and debt expense		(35,792)	(37,325)	(108,420)	(111,462)
Net loss before income taxes		(5,877)	7,377	(11,261)	16,795
Income tax (expense) benefit		(393)	583	(1,135)	(823)
Net (loss) income attributable to common stockholders		(6,958)	7,082	(9,880)	13,246
Unconsolidated Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Real estate, net		2,638,584		2,638,584		2,581,738
Cash and cash equivalents and restricted cash		112,392		112,392		75,071
Intangible assets, net		124,754		124,754		172,041
Other assets		46,816		46,816		36,218
Total assets		2,922,546		2,922,546		2,865,068
Notes and mortgages payable, net		1,753,699		1,753,699		1,648,403
Intangible liabilities, net		29,106		29,106		38,377
Other liabilities		93,518		93,518		65,759
Total liabilities		1,876,323		1,876,323		1,752,539
Equity		1,046,223		1,046,223		1,112,529
Total liabilities and equity		2,922,546		2,922,546		$ 2,865,068
Rental revenue		61,340	40,361	182,923	115,041
Fee and other income		625	827	2,149	1,317
Total revenues		61,965	41,188	185,072	116,358
Operating		26,381	17,670	81,963	47,347
Depreciation and amortization		29,700	17,252	88,981	46,459
Total expenses		56,081	34,922	170,944	93,806
Interest and other (loss) income, net		(45)	179	3	478
Interest and debt expense		(14,030)	(12,902)	(44,244)	(36,752)
Net loss before income taxes		(8,191)	(6,457)	(30,113)	(13,722)
Income tax (expense) benefit		(1)	2	(45)	(6)
Net (loss) income attributable to common stockholders		$ (8,192)	$ (6,455)	$ (30,158)	$ (13,728)

[1] Represents the consolidated assets and liabilities of Paramount Group Operating Partnership LP, a Delaware limited partnership (the “Operating Partnership”). The Operating Partnership is a consolidated variable interest entity (“VIE”), of which we are the sole general partner and own approximately 91.4% as of September 30, 2020. The assets and liabilities of the Operating Partnership, as of September 30, 2020, include $4,022,342 and $2,546,278 of assets and liabilities, respectively, of certain VIEs that are consolidated by the Operating Partnership. See Note 12, Variable Interest Entities (“VIEs”).