Income Taxes - Additional Information (Detail) - 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]
Income tax provision	$ 20,651	$ 11,555	$ 40,609	$ 16,422
Effective income tax rate	25.70%	24.90%	24.90%	25.10%