Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Sep. 30, 2021
Assets:
Cash and cash equivalents	$ 75,830	$ 114,314
Short-term investments	22,682	19,667
Other assets	7,569	9,100
Liabilities:
Deferred compensation	8,052	8,527
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and cash equivalents	75,830	114,314
Short-term investments	22,682	19,667
Other assets	0	0
Liabilities:
Deferred compensation	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Cash and cash equivalents	0	0
Short-term investments	0	0
Other assets	7,569	9,100
Liabilities:
Deferred compensation	8,052	8,527
Significant Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents	0	0
Short-term investments	0	0
Other assets	0	0
Liabilities:
Deferred compensation	$ 0	$ 0