Equity-Based Compensation - Unvested Units After Expected Forfeitures which are Expected to Vest (Details)	3 Months Ended
	Mar. 31, 2017 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	18,043,121
Weighted-average service period of unit expected to vest (in years)	1 year 9 months 18 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	6,545,070
Weighted-average service period of unit expected to vest (in years)	1 year 3 months 18 days
PJT Partners Holdings LP | Partnership Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	11,498,051
Weighted-average service period of unit expected to vest (in years)	2 years