Stock-Based Compensation (Tables)

6 Months Ended

Mar. 31, 2022

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of stock-based compensation expense

	Three Months Ended March 31,				Six Months Ended March 31,
	2022		2021		2022		2021
Restricted stock units	$	8,058	$	7,048	$	15,255	$	13,192
Employee stock purchase plan		599		433		1,293		999
Total stock-based compensation expense	$	8,657	$	7,481	$	16,548	$	14,191

Restricted Stock Unit Activity

		Time-Based	Stock	Performance-
	Total Units	Units	Grants	Based Units
Six months ended March 31, 2022	228,468	101,706	16,286	110,476
Six months ended March 31, 2021	329,801	149,249	14,657	165,895

		Weighted
		Average
		Grant-Date
	Shares	Fair Value
Outstanding at September 30, 2021	1,088,652	$	47.35
Granted	228,468		103.31
Vested	(208,713)		40.03
Forfeited	(553,624)		39.30
Outstanding at March 31, 2022	554,783		75.14