Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock, Common	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Beginning balance (in shares) at Sep. 30, 2021		40,653	6,391
Beginning balance at Sep. 30, 2021	$ 472,517	$ 407	$ (56,535)	$ 370,699	$ 180,692	$ (22,746)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,160				8,160
Other comprehensive (loss) income	(1,519)					(1,519)
Employee stock purchase plan issuances (in shares)			(60)
Employee stock purchase plan issuances	1,101		$ 547	554
Taxes paid for net share settlement of share-based payment awards (in shares)			96
Taxes paid for net share settlement of share-based payment awards	(6,476)		$ (2,177)	4,299
Issuance of stock under stock award plans (in shares)		1,024
Issuance of stock under stock award plans	6,737	$ 10		6,727
Stock-based compensation expense	6,402			6,402
Ending balance (in shares) at Jun. 30, 2022		41,677	6,427
Ending balance at Jun. 30, 2022	486,922	$ 417	$ (58,165)	380,083	188,852	(24,265)
Beginning balance (in shares) at Mar. 31, 2022		41,525	6,447
Beginning balance at Mar. 31, 2022	480,504	$ 415	$ (58,310)	376,579	184,726	(22,906)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,126				4,126
Other comprehensive (loss) income	(1,359)					(1,359)
Employee stock purchase plan issuances (in shares)			(23)
Employee stock purchase plan issuances	430		$ 213	217
Taxes paid for net share settlement of share-based payment awards (in shares)			3
Taxes paid for net share settlement of share-based payment awards	(68)		$ (68)
Issuance of stock under stock award plans (in shares)		152
Issuance of stock under stock award plans	1,146	$ 2		1,144
Stock-based compensation expense	2,143			2,143
Ending balance (in shares) at Jun. 30, 2022		41,677	6,427
Ending balance at Jun. 30, 2022	486,922	$ 417	$ (58,165)	380,083	188,852	(24,265)
Beginning balance (in shares) at Sep. 30, 2022		41,950	6,413
Beginning balance at Sep. 30, 2022	501,513	$ 420	$ (58,172)	385,244	200,075	(26,054)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,405				18,405
Other comprehensive (loss) income	1,358					1,358
Employee stock purchase plan issuances (in shares)			(58)
Employee stock purchase plan issuances	1,690		$ 553	1,137
Taxes paid for net share settlement of share-based payment awards (in shares)			97
Taxes paid for net share settlement of share-based payment awards	(3,851)		$ (3,851)	0
Issuance of stock under stock award plans (in shares)		458
Issuance of stock under stock award plans	2,616	$ 4		2,612
Stock-based compensation expense	9,852			9,852
Ending balance (in shares) at Jun. 30, 2023		42,408	6,452
Ending balance at Jun. 30, 2023	531,583	$ 424	$ (61,470)	398,845	218,480	(24,696)
Beginning balance (in shares) at Mar. 31, 2023		42,325	6,464
Beginning balance at Mar. 31, 2023	520,179	$ 423	$ (61,446)	394,036	211,753	(24,587)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,727				6,727
Other comprehensive (loss) income	(109)					(109)
Employee stock purchase plan issuances (in shares)			(18)
Employee stock purchase plan issuances	520		$ 173	347
Taxes paid for net share settlement of share-based payment awards (in shares)			6
Taxes paid for net share settlement of share-based payment awards	(197)		$ (197)
Issuance of stock under stock award plans (in shares)		83
Issuance of stock under stock award plans		$ 1		943
Stock-based compensation expense	3,519			3,519
Ending balance (in shares) at Jun. 30, 2023		42,408	6,452
Ending balance at Jun. 30, 2023	$ 531,583	$ 424	$ (61,470)	$ 398,845	$ 218,480	$ (24,696)