Profit Sharing Plan (Details) - Multiple employer 401(k) profit sharing plan $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) year	Jun. 30, 2019 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, requisite service period			1 year
Defined contribution plan, minimum age requirement (years of age) | year			21
Contributions by the Company | $	$ 1.8	$ 1.5	$ 5.1	$ 4.4