Earnings per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Basic earnings per common share:
Net income - basic	$ 15,721	$ 4,299
Weighted shares outstanding - basic (in shares)	56,183	55,361
Basic earnings per common share (in dollars per share)	$ 0.28	$ 0.08
Diluted earnings per common share:
Net income - basic	$ 15,721	$ 4,299
Add: Convertible Notes interest expense, net of tax	1,884	0
Net income - diluted	$ 17,605	$ 4,299
Weighted shares outstanding - basic (in shares)	56,183	55,361
Effect of dilution from equity-based compensation awards (in shares)	541	67
Effect of dilution from if-converted Convertible Notes (in shares)	25,224	0
Weighted shares outstanding - diluted (in shares)	81,948	55,428
Diluted earnings per common share (in dollars per share)	$ 0.21	$ 0.08
Potential common shares excluded from the calculation of diluted earnings per share above, Restricted stock (in shares)	1,936	657