Quarterly report pursuant to Section 13 or 15(d)

Acquisitions - Additional Information (Detail)

v3.19.2
Acquisitions - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Jul. 01, 2019
Apr. 12, 2019
Dec. 13, 2018
Dec. 15, 2015
Mar. 30, 2015
May 31, 2019
Mar. 31, 2019
Jun. 30, 2018
Jun. 30, 2019
Dec. 31, 2018
Class B Common Stock                    
Business Acquisition [Line Items]                    
Issuance of Class B shares, Shares           948 2,000 6,000    
Cortina Asset Management, LLC | Purchase Agreement                    
Business Acquisition [Line Items]                    
Percentage to acquire business in cash   80.00%                
Additional percentage to acquire business in cash   80.00%                
Cortina Asset Management, LLC | Purchase Agreement | Subsequent Event                    
Business Acquisition [Line Items]                    
Aggregate purchase amount $ 33,577                  
Additional percentage to acquire business in cash 80.00%                  
Cortina Asset Management, LLC | Purchase Agreement | Maximum                    
Business Acquisition [Line Items]                    
Aggregate purchase amount   $ 44,937,000                
Additional aggregate purchase amount   $ 26,209,000                
Cortina Asset Management, LLC | Purchase Agreement | Maximum | Subsequent Event                    
Business Acquisition [Line Items]                    
Additional aggregate purchase amount $ 26,209                  
Cortina Asset Management, LLC | Purchase Agreement | SLP                    
Business Acquisition [Line Items]                    
Percentage of business combination consideration issuance   20.00%                
Additional percentage of earn out payment paid in cash   20.00%                
Potential earn-out payments period   4 years                
Cortina Asset Management, LLC | Purchase Agreement | SLP | Subsequent Event                    
Business Acquisition [Line Items]                    
Additional aggregate purchase amount $ 8,952                  
Additional percentage of earn out payment paid in cash 20.00%                  
Potential earn-out payments period 4 years                  
Cortina Asset Management, LLC | Purchase Agreement | SLP | Class B Common Stock | Subsequent Event                    
Business Acquisition [Line Items]                    
Issuance of Class B shares, Shares 662,713                  
Neosho                    
Business Acquisition [Line Items]                    
Cash paid on date of acquisition     $ 399,000           $ 399,000  
Equity consideration for SLP acquired     20,000           1,686,000  
Contingent consideration     1,686,000              
Expected payments on first anniversary of closing date     300,000              
Earn out payments due in two years     100,000              
Earn out payments due in three years     100,000              
Earn out payments due in four years     100,000              
Earn out payments due in five years     $ 100,000              
Percentage of product to obtain earn out payment     50.00%              
Percentage of earn out payment paid in cash     75.00%              
Percentage of earn out payment paid in equity     25.00%              
Cappiccille                    
Business Acquisition [Line Items]                    
Equity consideration for SLP acquired                 126,000 $ 231,000
Contingent consideration       $ 354,000            
Cash paid on date of acquisition       $ 148,000            
Earn out payments percentage on revenue remainder of fiscal year       19.00%            
Earn out payments percentage on revenue due in two years       19.00%            
Earn out payments percentage on revenue due in three years       19.00%            
Earn out payments percentage on revenue due in four years       19.00%            
Earn out payments percentage on revenue due thereafter       19.00%            
Jamison                    
Business Acquisition [Line Items]                    
Equity consideration for SLP acquired         $ 3,562,000          
Contingent consideration         1,429,000       $ 204,000 $ 524,000
Cash paid on date of acquisition         $ 3,550,000          
Earn out payments percentage on EBITDA remainder of fiscal year         20.00%          
Earn out payments percentage on EBITDA due in two years         20.00%          
Earn out payments percentage on EBITDA due in three years         20.00%          
Earn out payments percentage on EBITDA due in four years         20.00%          
Earn out payments percentage on EBITDA due in five years         20.00%          
Earn Out Payments Percentage On EBITDA Due thereafter         20.00%          
Jamison | Seller Note                    
Business Acquisition [Line Items]                    
Promissory note issued         $ 394,000          
Interest on principal amount         5.00%          
Jamison | Principals Notes                    
Business Acquisition [Line Items]                    
Promissory note issued         $ 1,771,000          
Interest on principal amount         5.00%