CONDENSED CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	COMMON STOCK	CAPITAL IN EXCESS OF PAR VALUE	RETAINED EARNINGS	TREASURY SHARES	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	DEFERRED COMPENSATION
Balance (in shares) at Sep. 30, 2020		83,739			27,610
Balance at Sep. 30, 2020	$ 700,151	$ 20,935	$ 583,008	$ 607,518	$ (413,493)	$ (72,092)	$ (25,725)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	29,500			29,500
Dividend	(4,469)			(4,469)
Shares withheld on employee taxes on vested equity awards (in shares)					133
Shares withheld on employee taxes on vested equity awards	(2,909)				$ (2,909)
Amortization of deferred compensation	609						609
Equity awards granted, net (in shares)		494
Equity awards granted, net	0	$ 123	(123)
ESOP allocation of common stock	596		596
Stock-based compensation	3,428		3,428
Other comprehensive income, net of tax	13,141					13,141
Balance (in shares) at Dec. 31, 2020		84,233			27,743
Balance at Dec. 31, 2020	740,047	$ 21,058	586,909	632,549	$ (416,402)	(58,951)	(25,116)
Balance (in shares) at Sep. 30, 2021		84,375			27,762
Balance at Sep. 30, 2021	807,158	$ 21,094	602,181	669,998	$ (416,850)	(45,977)	(23,288)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	19,298			19,298
Dividend	(4,739)			(4,739)
Shares withheld on employee taxes on vested equity awards (in shares)					422
Shares withheld on employee taxes on vested equity awards	(10,886)				$ (10,886)
Amortization of deferred compensation	591						591
Equity awards granted, net (in shares)		113
Equity awards granted, net	0	$ 28	(28)
ESOP allocation of common stock	848		848
Stock-based compensation	2,866		2,866
Other comprehensive income, net of tax	(2,751)					(2,751)
Balance (in shares) at Dec. 31, 2021		84,488			28,184
Balance at Dec. 31, 2021	$ 812,385	$ 21,122	$ 605,867	$ 684,557	$ (427,736)	$ (48,728)	$ (22,697)