Quarterly report pursuant to Section 13 or 15(d)

Equity - Class A Common Stock (Detail)

v3.19.3
Equity - Class A Common Stock (Detail) - Class A Common Stock - shares
1 Months Ended
Aug. 31, 2019
Jun. 30, 2019
May 31, 2019
Mar. 31, 2019
Sep. 30, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Class Of Stock [Line Items]                    
Common stock, shares outstanding   8,624,000   8,535,000 9,180,013 8,518,096 8,346,000 8,306,000 8,259,000 8,142,000
Issuance of Class A common stock upon conversion of Class B units to Class A common stock 556,293 2,386 84,268 17,074            
Issuance of Class A common stock upon vesting of restricted stock units     1,896              
Common stock conversion date Aug. 31, 2019 Jun. 30, 2019 May 31, 2019 Mar. 31, 2019            
Stock issued upon vesting of restricted stock units, Transaction date     May 31, 2019