Basis of Presentation and Significant Accounting Policies - Summary of Reconciliation Net Income (Loss) Attributable to Estimated Taxable Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net income (loss) attributable to Paramount Group, Inc.	$ 5,318	$ 37,531	$ (34,816)	$ 1,114	$ (6,793)	$ (10,214)	$ 103,016	$ 372	$ 9,147	$ 86,381	$ (9,934)
Book to tax differences:
Straight-lining of rents and amortization of above and below-market leases, net									(48,604)	(44,083)	(51,880)
Depreciation and amortization									92,512	96,991	95,489
Stock-based compensation									17,847	14,441	9,673
Real estate impairment loss									41,788
Gain on sale of real estate									(14,381)	(95,182)
Write-off of and valuation allowance on preferred equity investment									(3,574)	4,327
Earnings of unconsolidated joint ventures, including real estate investments									179	(8,600)	(3,513)
Swap breakage costs										(1,487)	(25,367)
Unrealized gain on interest rate swaps										(860)	(4,651)
Other, net									(8,240)	1,885	13,295
Estimated taxable income									$ 86,674	$ 53,813	$ 23,112