CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings
Beginning balance (in shares) at Sep. 30, 2023		31,351,000
Beginning balance at Sep. 30, 2023	$ 1,102,819	$ 31	$ 864,778	$ 238,010
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income and comprehensive income	60,899			60,899
Stock-based compensation expense	3,062		3,062
Stock option exercises (in shares)		2,000
Stock option exercises	16		16
Shares issued under employee stock plans, net (in shares)		376,000
Shares issued under employee stock plans, net	1	$ 1
Forfeiture and other settlements of restricted stock (in shares)		(10,000)
Common stock redeemed for tax liability (in shares)		(172,000)
Common stock redeemed for tax liability	$ (5,220)		(5,220)
Share repurchases (in shares)	0
Ending balance (in shares) at Mar. 31, 2024		31,547,000
Ending balance at Mar. 31, 2024	$ 1,161,577	$ 32	862,636	298,909
Beginning balance (in shares) at Dec. 31, 2023		31,533,000
Beginning balance at Dec. 31, 2023	1,121,011	$ 32	861,241	259,738
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income and comprehensive income	39,171			39,171
Stock-based compensation expense	1,389		1,389
Stock option exercises (in shares)		2,000
Stock option exercises	16		16
Shares issued under employee stock plans, net (in shares)		14,000
Forfeiture and other settlements of restricted stock (in shares)		(2,000)
Common stock redeemed for tax liability (in shares)		0
Common stock redeemed for tax liability	$ (10)		(10)
Share repurchases (in shares)	0
Ending balance (in shares) at Mar. 31, 2024		31,547,000
Ending balance at Mar. 31, 2024	$ 1,161,577	$ 32	862,636	298,909
Beginning balance (in shares) at Sep. 30, 2024		31,048,000
Beginning balance at Sep. 30, 2024	1,232,111	$ 31	853,895	378,185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income and comprehensive income	15,908			15,908
Stock-based compensation expense	3,625		3,625
Stock option exercises (in shares)		11,000
Stock option exercises	106		106
Shares issued under employee stock plans, net (in shares)		274,000
Forfeiture and other settlements of restricted stock (in shares)		(30,000)
Common stock redeemed for tax liability (in shares)		(95,000)
Common stock redeemed for tax liability	$ (3,121)		(3,121)
Share repurchases (in shares)	(905,000)	(905,000)
Share repurchases	$ (20,562)	$ (1)	(20,561)
Ending balance (in shares) at Mar. 31, 2025		30,303,000
Ending balance at Mar. 31, 2025	1,228,067	$ 30	833,944	394,093
Beginning balance (in shares) at Dec. 31, 2024		31,202,000
Beginning balance at Dec. 31, 2024	1,234,048	$ 31	852,702	381,315
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income and comprehensive income	12,778			12,778
Stock-based compensation expense	1,712		1,712
Stock option exercises (in shares)		11,000
Stock option exercises	106		106
Shares issued under employee stock plans, net (in shares)		7,000
Forfeiture and other settlements of restricted stock (in shares)		(11,000)
Common stock redeemed for tax liability (in shares)		(1,000)
Common stock redeemed for tax liability	$ (15)		(15)
Share repurchases (in shares)	(905,000)	(905,000)
Share repurchases	$ (20,562)	$ (1)	(20,561)
Ending balance (in shares) at Mar. 31, 2025		30,303,000
Ending balance at Mar. 31, 2025	$ 1,228,067	$ 30	$ 833,944	$ 394,093