Earnings Per Share - Schedule of Earnings Per Share. Basic and Dilutive (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Income from continuing operations	$ 34,707	$ 44,678	$ 59,115	$ 79,573
Loss from discontinued operations, net of tax	0	(6)	(77)	(16)
Net income	$ 34,707	$ 44,672	$ 59,038	$ 79,557
Denominator:
Basic weighted-average shares (in shares)	30,394	30,594	30,464	30,464
Dilutive effect of restricted stock awards (in shares)	211	222	234	300
Dilutive effect of stock options (in shares)	5	7	4	8
Dilutive weighted-average shares (in shares)	30,610	30,823	30,702	30,772
Basic income per share:
Continuing operations (in USD per share)	$ 1.14	$ 1.46	$ 1.94	$ 2.61
Discontinued operations (in USD per share)	0	0	0	0
Total (in USD per share)	1.14	1.46	1.94	2.61
Diluted income per share:
Continuing operations (in USD per share)	1.13	1.45	1.93	2.59
Discontinued operations (in USD per share)	0	0	0	0
Total (in USD per share)	$ 1.13	$ 1.45	$ 1.93	$ 2.59