Transactions With Related Parties - Additional Information (Details) - USD ($)			3 Months Ended		12 Months Ended
	Feb. 16, 2017	Feb. 13, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Professional fees					$ 18,925,000	$ 19,814,000	$ 10,837,000
Due to and from settlement of non cash contributions					8,566,000
Advisory Fees					377,610,000	$ 286,014,000	$ 271,278,000
Percentage of advisory fees earned from affiliates						1.50%	11.80%
Placement Fees					114,968,000	$ 114,058,000	$ 127,664,000
Percentage of placement fees earned from affiliates						12.60%	11.70%
Severance Accrued (Reversed)					0	$ (2,600,000)	$ 19,800,000
Non-cash equity-based compensation expense							5,200,000
Forfeiture Accrual			$ 500,000		500,000	1,300,000
Aggregate payment on exchange of partnership units settled					(170,000)
Aggregate payment on exchange of partnership units settled					16,054,000
Amount Due Pursuant to Tax Receivable Agreement			964,000		964,000
Unsecured Promissory Notes
Related Party Transaction [Line Items]
Promissory notes						600,000
Notes payable, spread on variable prime rate				1.00%
Blackstone
Related Party Transaction [Line Items]
Professional fees					300,000	0	0
Amounts payable related to certain professional fees			300,000		300,000
Amounts payable related to certain purchases of furniture, equipment and leasehold improvements			0		0	4,000,000
Receivable from former parent for accounts receivable balance						4,500,000
Due to and from settlement of non cash contributions					8,566,000
Amount payable under transition services agreement			25,000		25,000	500,000
Tax benefit accrual			$ 4,100,000		4,100,000
Affiliates
Related Party Transaction [Line Items]
Advisory Fees					0	4,220,000	31,948,000
Placement Fees					0	14,329,000	14,911,000
Affiliates | Interest Income
Related Party Transaction [Line Items]
Interest income earned from affiliates					$ 0	$ 200,000	$ 300,000
PJT Partners Holdings LP
Related Party Transaction [Line Items]
Exchange of partnership units settled			361,588		594,072
Aggregate payment on exchange of partnership units settled					$ 16,054,000
Percentage payment to exchanging holders of partnership units of benefits					85.00%
Amount Due Pursuant to Tax Receivable Agreement			$ 964,000		$ 964,000
PJT Partners Holdings LP | Subsequent Event
Related Party Transaction [Line Items]
Aggregate payment on exchange of partnership units settled	$ 13,000,000
Price per partnership unit paid equal to the volume-weighted average price of share		$ 36.09