Silvercrest Asset Management Group LLC Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Additional Information (Detail)

Commitments and Contingencies - Additional Information (Detail) - USD ($)			1 Months Ended											3 Months Ended		9 Months Ended
	Jan. 16, 2018	Jun. 30, 2015	Mar. 31, 2018	Jan. 31, 2018	Jul. 31, 2017	Jan. 31, 2017	Sep. 30, 2016	Jan. 31, 2016	Dec. 31, 2015	Oct. 31, 2015	Jul. 31, 2015	Jun. 30, 2015	Mar. 31, 2014	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Commitments And Contingencies [Line Items]
Operating lease rent expense														$ 1,450,000	$ 996,000	$ 4,348,000	$ 2,908,000
Sub-lease income														29,000	68,000	187,000	202,000
Assets acquired under capital leases																11,000	241,000
Depreciation expense														179,000	247,000	567,000	681,000
Capital Lease Assets
Commitments And Contingencies [Line Items]
Depreciation expense														40,000	36,000	101,000	110,000
Additional Office Space
Commitments And Contingencies [Line Items]
Operating lease rent expense, net							$ 10,000						$ 5,000
Refundable security deposit													$ 3,000
Lease commencement date							Oct. 01, 2017						May 01, 2014
Lease expires							Nov. 30, 2024						Jul. 31, 2019
Number of rent free periods													3 months
Rent credit							$ 40,000
Additional Office Space \| Amendment Number Two
Commitments And Contingencies [Line Items]
Lease commencement date	Jan. 16, 2018
Lease expires	Nov. 30, 2028
Lease expansion date	Jan. 12, 2018
Office Space \| Charlottesville, VA.
Commitments And Contingencies [Line Items]
Operating lease rent expense, net												$ 2,000
Refundable security deposit		$ 2,000										$ 2,000
Lease commencement date												Jun. 30, 2015
Lease expires												Jun. 30, 2018
Office Space \| Bedminster, NJ.
Commitments And Contingencies [Line Items]
Operating lease rent expense, net																$ 11,000
Lease expires																Mar. 31, 2022
Number of rent free periods																4 months
Office Space \| Princeton, NJ.
Commitments And Contingencies [Line Items]
Operating lease rent expense, net								$ 6,000								$ 5,000
Lease expires								Aug. 31, 2022								Apr. 30, 2016
Number of rent free periods								5 months
Office Space \| New York City
Commitments And Contingencies [Line Items]
Operating lease rent expense, net									$ 446,000
Lease commencement date									Oct. 01, 2017
Lease expires									Sep. 30, 2028
Number of rent free periods									12 months
Payments for tenant improvements									$ 2,080,000
Office Space \| Livingston, NJ
Commitments And Contingencies [Line Items]
Operating lease rent expense, net								$ 2,000
Office Space \| Boston, MA
Commitments And Contingencies [Line Items]
Operating lease rent expense, net				$ 33,000
Lease commencement date				Jan. 01, 2018
Lease expires				Apr. 30, 2023
Number of rent free periods				1 month
Office Space \| Extended Lease Agreement \| Charlottesville, VA.
Commitments And Contingencies [Line Items]
Lease commencement date												Jul. 01, 2018
Lease expires												Jun. 30, 2019
Lease extended period												1 year
Office Equipment
Commitments And Contingencies [Line Items]
Capital lease obligation														$ 224,000		$ 224,000		$ 299,000
Office Equipment \| Telephone System
Commitments And Contingencies [Line Items]
Lease expires																Nov. 30, 2018
Assets acquired under capital leases																$ 321,000
Capital lease, period														5 years		5 years
Capital lease, minimum monthly payment																$ 5,000
Office Equipment \| Copier
Commitments And Contingencies [Line Items]
Lease expires			Feb. 28, 2021			Dec. 31, 2018				Oct. 31, 2018	Jun. 30, 2018
Assets acquired under capital leases			$ 11,000			$ 11,000				$ 18,000	$ 21,000
Capital lease, period			3 years			2 years				3 years	3 years
Capital lease, minimum monthly payment			$ 300			$ 1,000				$ 1,000	$ 1,000
Office Equipment \| Two Copiers
Commitments And Contingencies [Line Items]
Lease expires						Jan. 31, 2022
Assets acquired under capital leases						$ 152,000
Capital lease, period						5 years
Capital lease, minimum monthly payment						$ 3,000
Office Equipment \| Four Copiers
Commitments And Contingencies [Line Items]
Lease expires					Jun. 30, 2020
Assets acquired under capital leases					$ 72,000
Capital lease, period					3 years
Capital lease, minimum monthly payment					$ 2,000
Office Equipment \| Jamison
Commitments And Contingencies [Line Items]
Assets acquired under capital leases		$ 253,000
Letter of Credit
Commitments And Contingencies [Line Items]
Refundable security deposit														$ 506,000		506,000		$ 506,000
Letter of Credit \| Boston landlord
Commitments And Contingencies [Line Items]
Refundable security deposit														80,000		80,000
General and administrative
Commitments And Contingencies [Line Items]
Operating lease rent expense, net														$ 1,421,000	$ 928,000	$ 4,161,000	$ 2,706,000