Shareholders’ Equity (Details)	12 Months Ended
	Sep. 30, 2020 vote shares
Class A common shares
Class of Stock [Line Items]
Number of votes for each share held | vote	1
Class B-1 common shares
Class of Stock [Line Items]
Number of votes for each share held | vote	10
Conversion ratio	1
Membership units (in units)	1,000,000
Class B-2 common shares
Class of Stock [Line Items]
Number of votes for each share held | vote	10
Conversion ratio	1
Class A membership units
Class of Stock [Line Items]
Conversion ratio	1
Class A membership units | Class A common shares
Class of Stock [Line Items]
Membership units (in units)	15,395,641
ABP Trust | Class B-2 common shares
Class of Stock [Line Items]
Membership units (in units)	15,000,000
ABP Trust | Class A membership units
Class of Stock [Line Items]
Membership units (in units)	15,000,000