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, 2021	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Income (loss) from continuing operations	$ 122,180	$ 53,316	$ (79,421)
Loss from discontinued operations, net of tax	(159)	(1,090)	(99)
Net income (loss)	$ 122,021	$ 52,226	$ (79,520)
Denominator:
Basic weighted-average shares (in shares)	29,954	29,704	30,617
Dilutive effect of restricted stock awards (in shares)	461	229	0
Dilutive effect of stock options (in shares)	22	15	0
Diluted weighted-average shares (in shares)	30,437	29,948	30,617
Basic income (loss) per share:
Continuing operations (in dollars per share)	$ 4.08	$ 1.80	$ (2.59)
Discontinued operations (in dollars per share)	(0.01)	(0.04)	(0.01)
Total (in dollars per share)	4.07	1.76	(2.60)
Diluted income (loss) per share:
Continuing operations (in dollars per share)	4.01	1.78	(2.59)
Discontinued operations (in dollars per share)	0	(0.04)	(0.01)
Total (in dollars per share)	$ 4.01	$ 1.74	$ (2.60)