Equity-Based and Other Deferred Compensation - Unvested Units After Expected Forfeitures which are Expected to Vest (Details)	3 Months Ended
	Mar. 31, 2022 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	6,637,232
Weighted-average service period of unit expected to vest (in years)	2 years 3 months 18 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	5,431,907
Weighted-average service period of unit expected to vest (in years)	2 years 2 months 12 days
Restricted Share Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	2,584
Weighted-average service period of unit expected to vest (in years)	6 months
PJT Partners Holdings LP | Partnership Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	1,202,741
Weighted-average service period of unit expected to vest (in years)	2 years 9 months 18 days