Stockholder's Equity - Additional Information (Details) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) Vote $ / shares shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Feb. 06, 2024 USD ($)	Apr. 25, 2022 USD ($)
Class Of Stock [Line Items]
Number of vested and unvested partnership units | shares	10.2
Aggregate amount of shares repurchased	$ 116,738,000	$ 109,484,000	$ 103,342,000
Treasury stock purchases	$ 116,738,000	$ 109,484,000	$ 103,342,000
PJT Partners Holdings LP
Class Of Stock [Line Items]
Voting power	100.00%
Non-controlling interest percentage	39.00%	37.60%
PJT Partners Holdings LP | Maximum
Class Of Stock [Line Items]
Economic interest	100.00%
Class A Common Stock
Class Of Stock [Line Items]
Common stock, voting rights, votes per share | Vote	1
Share repurchase program, authorized amount					$ 200,000,000
Share repurchase program, remaining authorized amount	$ 57,000,000
Treasury stock repurchased | shares	1.6
Treasury stock, average price per share | $ / shares	$ 73.50
Aggregate amount of shares repurchased	$ 116,700,000
Class A Common Stock | Subsequent Event
Class Of Stock [Line Items]
Share repurchase program, authorized amount				$ 500,000,000
Class B Common Stock
Class Of Stock [Line Items]
Common stock, voting rights, votes per share | Vote	1