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, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Income from continuing operations	$ 24,643	$ 10,615	$ 36,679	$ 13,419
Loss from discontinued operations, net of tax	(115)	(1)	(154)	(59)
Net income	$ 24,528	$ 10,614	$ 36,525	$ 13,360
Denominator:
Basic weighted-average shares (in shares)	29,953	29,868	29,862	29,808
Dilutive effect of restricted stock awards (in shares)	231	97	262	250
Dilutive effect of stock options (in shares)	31	10	26	20
Dilutive weighted-average shares (in shares)	30,215	29,975	30,150	30,078
Basic income (loss) per share:
Continuing Operations (in USD per share)	$ 0.82	$ 0.36	$ 1.23	$ 0.45
Discontinued operations (in USD per share)	0	0	(0.01)	0
Total (in USD per share)	0.82	0.36	1.22	0.45
Diluted income (loss) per share:
Continuing operations (in USD per share)	0.81	0.35	1.22	0.45
Discontinued operations (in USD per share)	0	0	(0.01)	0
Total (in USD per share)	$ 0.81	$ 0.35	$ 1.21	$ 0.45