Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019
Common Stock Class A Non-voting
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01000
Common stock, shares authorized (shares)	100,000,000	100,000,000	100,000,000
Common stock, shares issued (shares)	52,097,590	52,565,064	52,475,070
Common stock, shares outstanding (shares)	52,097,590	52,565,064	52,475,070
Common Stock Class B Voting
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01000
Common stock, shares authorized (shares)	3,000,000	3,000,000	3,000,000
Common stock, shares issued (shares)	2,970,171	2,970,171	2,970,171.000
Common stock, shares outstanding (shares)	2,970,171	2,970,171	2,970,171