Shareholders’ Equity - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Mar. 11, 2021 $ / shares shares	Mar. 31, 2021 USD ($) vesting_installment shares	Mar. 31, 2020 USD ($)	Mar. 31, 2021 USD ($) vesting_installment shares	Mar. 31, 2020 USD ($)
Class of Stock [Line Items]
General and administrative | $		$ 7,104	$ 7,297	$ 13,364	$ 14,343
Equity based compensation expense | $		$ 546	$ 592	$ 1,104	$ 1,226
Unvested shares outstanding (in shares)		129,570		129,570
Vesting 2021
Class of Stock [Line Items]
Shares vesting (in shares)				45,020
Vesting 2022
Class of Stock [Line Items]
Shares vesting (in shares)				37,550
Vesting 2023
Class of Stock [Line Items]
Shares vesting (in shares)				29,660
Vesting 2024
Class of Stock [Line Items]
Shares vesting (in shares)				17,340
Class A Common Stock | 2016 Omnibus Equity Plan
Class of Stock [Line Items]
Number of annual installments | vesting_installment		5		5
Shares granted (in shares)	3,000
Price per share (in dollars per share) | $ / shares	$ 42.85
General and administrative | $		$ 771		$ 771
Shares repurchased (in shares)				450
Shares repurchased during period | $				$ 19