Quarterly report pursuant to Section 13 or 15(d)

Equity - Additional Information (Detail)

v3.19.2
Equity - Additional Information (Detail) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2019
May 31, 2019
Mar. 31, 2019
Jan. 31, 2019
Jun. 30, 2019
Mar. 31, 2019
Jun. 30, 2018
Mar. 31, 2018
Jun. 30, 2019
Jun. 30, 2018
Class Of Stock [Line Items]                    
Partnership distributions, amount         $ 3,474   $ 2,940   $ 5,759 $ 5,012
Distributions of partner incentive allocations of net income                 27,199 24,935
Class B Common Stock                    
Class Of Stock [Line Items]                    
Share conversion, Shares         (87,000) (17,000) (45,000) (117,000)    
Issuance of common stock   948       2,000 6,000      
Class B Common Stock | Resale And Registration Rights Agreement                    
Class Of Stock [Line Items]                    
Share conversion, Shares 2,386 84,268 17,074              
Class B Common Stock | Neosho                    
Class Of Stock [Line Items]                    
Issuance of Class B common stock in connection with the Neosho Acquisition       1,516            
Class A Common Stock                    
Class Of Stock [Line Items]                    
Share conversion, Shares         87,000 17,000 45,000 117,000    
Issuance of common stock   1,896                
Silvercrest L.P                    
Class Of Stock [Line Items]                    
Accrued partner incentive allocations         $ 6,261   $ 7,138   $ 11,651 $ 13,901