Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income tax expense	$ 2,608	$ 2,226	$ 8,944	$ 24,335
Federal income tax expense	1,900	1,624	6,578	17,756
State income tax expense	$ 708	$ 602	$ 2,366	$ 6,579