Quarterly report pursuant to Section 13 or 15(d)

Stockholders' equity - Schedule of equity awards (Detail)

v3.20.2
Stockholders' equity - Schedule of equity awards (Detail) - Employee stock option - $ / shares
3 Months Ended 12 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock Options,Outstanding, beginning of period 70,161  
Stock Options, Forfeited (444)  
Stock Options, Outstanding, end of period 69,717 70,161
Stock Options, Exercisable, end of period 43,273  
Exercise price, beginning of period $ 60.42  
Weighted-average Exercise Price, Forfeited 69.32  
Weighted-average Exercise Price, Exercise price, end of period 60.00 $ 60.42
Weighted-average Exercise Price, Exercisable, end of period $ 68.53  
Weighted-average Remaining Contractual Term, Outstanding 2 years 10 months 20 days 2 years 7 months 24 days
Weighted-average Remaining Contractual Term, Exercisable 2 years 3 months 3 days