Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Estimated Annual Effective Tax Rate Used to Calculate Income Tax Expense (Benefit)			19.70%	3.90%
Federal statutory income tax rate, percent			21.00%	21.00%
Effective income tax rate reconciliation, percent	22.70%	3.30%	23.70%	3.90%
Income tax expense	$ (3,887)	$ (740)	$ (7,672)	$ (3,336)
Income before income taxes	17,086	22,581	32,430	86,593
Unrecognized Tax Benefits	$ 1,805	$ 1,313	$ 1,805	$ 1,313