Equity-Based Compensation - Unvested Units After Expected Forfeitures which are Expected to Vest (Details)	12 Months Ended
	Dec. 31, 2016 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	16,926,734
Weighted-average service period of unit expected to vest (in years)	1 year 10 months 24 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units expected to vest	5,852,412
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	11,074,322
Weighted-average service period of unit expected to vest (in years)	2 years 3 months 18 days