Quarterly report pursuant to Section 13 or 15(d)

Equity (Detail)

v3.20.2
Equity (Detail)
$ / shares in Units, $ in Millions
1 Months Ended 9 Months Ended
Jun. 30, 2020
USD ($)
voting_rights
$ / shares
shares
Jun. 30, 2020
voting_rights
$ / shares
shares
Sep. 30, 2019
shares
Class A Common Stock      
Schedule Of Stockholders Equity [Line Items]      
Voting rights | voting_rights 1 1  
Conversion rate   1  
Common stock, shares outstanding (in shares) 33,430,364 33,430,364 32,597,736
Class A Common Stock | Secondary Offering [Member]      
Schedule Of Stockholders Equity [Line Items]      
Number of shares issued in transaction (in shares) 5,750,000    
Sale of stock, price per share (usd per share) | $ / shares $ 16.50 $ 16.50  
Additional shares issued (in shares) 862,500 862,500  
Payments of stock issuance costs | $ $ 0.2    
Class B Common Stock      
Schedule Of Stockholders Equity [Line Items]      
Voting rights | voting_rights 10 10  
Conversion of Class B common stock to Class A common stock (in shares)   832,628  
Common stock, shares outstanding (in shares) 18,351,381 18,351,381 19,184,009