Transactions With Related Parties - Additional Information (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 09, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)
Related Party Transaction [Line Items]
Cash settled exchange of partnership units		$ 101,895	$ 18,953	$ 68,928
Amount due to tax receivable agreement		19,573	$ 9,289
Tax receivable agreement, 2021		1,000
Tax receivable agreement, 2022		700
Tax receivable agreement, 2023		1,300
Tax receivable agreement, 2024		1,300
Tax receivable agreement, 2025		1,300
Tax receivable agreement, Thereafter		$ 13,900
PJT Partners Holdings LP
Related Party Transaction [Line Items]
Exchange of partnership units settled | shares		1,700,000	400,000
Percentage payment to exchanging holders of partnership units of benefits		85.00%
PJT Partners Holdings LP | Subsequent Event
Related Party Transaction [Line Items]
Exchange of partnership units settled | shares	680,368
Cash settled exchange of partnership units	$ 48,500
Price per partnership unit paid equal to the volume-weighted average price of share | $ / shares	$ 71.25
Class A Common Stock | PJT Partners Holdings LP
Related Party Transaction [Line Items]
Exchange of Partnership unit to shares, number of shares per each unit		1