Earnings Per Share - Schedule of Earnings Per Share, Basic and Dilutive (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Income from continuing operations	$ 158,688	$ 220,718	$ 122,180
Loss from discontinued operations, net of tax	(77)	(14)	(159)
Net income	$ 158,611	$ 220,704	$ 122,021
Denominator:
Basic weighted-average shares (in shares)	30,353	30,432	29,954
Dilutive effect of restricted stock awards (in shares)	388	357	461
Dilutive effect of stock options (in shares)	6	7	22
Diluted weighted-average shares (in shares)	30,747	30,796	30,437
Basic income (loss) per share:
Continuing operations (in dollars per share)	$ 5.23	$ 7.25	$ 4.08
Discontinued operations (in dollars per share)	0	0	(0.01)
Total (in dollars per share)	5.23	7.25	4.07
Diluted income per share:
Continuing operations (in dollars per share)	5.16	7.17	4.01
Discontinued operations (in dollars per share)	0	0	0
Total (in dollars per share)	$ 5.16	$ 7.17	$ 4.01