Annual report pursuant to Section 13 and 15(d)

Income taxes - Summary of Income Tax Contingencies (Details)

v3.20.2
Income taxes - Summary of Income Tax Contingencies (Details) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2018
Reconciliation of the beginning and ending amount of gross unrecognized tax benefits      
Balance at beginning of year $ 3,001 $ 721 $ 633
Increases for tax positions taken in current year 770 2,280 88
Decreases for tax positions taken in current year (1,973) 0 0
Balance at end of year $ 1,798 $ 3,001 $ 721