CONDENSED CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	COMMON STOCK	CAPITAL IN EXCESS OF PAR VALUE	RETAINED EARNINGS	TREASURY SHARES	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	DEFERRED COMPENSATION
Beginning balance (in shares) at Sep. 30, 2020		83,739,000
Beginning balance (in shares) at Sep. 30, 2020					27,610,000
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)					133,000
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)		494,000
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
Ending balance (in shares) at Dec. 31, 2020		84,233,000
Ending balance (in shares) at Dec. 31, 2020					27,743,000
Balance at Dec. 31, 2020	740,047	$ 21,058	586,909	632,549	$ (416,402)	(58,951)	(25,116)
Beginning balance (in shares) at Sep. 30, 2020		83,739,000
Beginning balance (in shares) at Sep. 30, 2020					27,610,000
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	63,319
Ending balance (in shares) at Jun. 30, 2021		84,420,000
Ending balance (in shares) at Jun. 30, 2021					27,743,000
Balance at Jun. 30, 2021	785,341	$ 21,104	597,368	658,605	$ (416,402)	(51,437)	(23,897)
Beginning balance (in shares) at Dec. 31, 2020		84,233,000
Beginning balance (in shares) at Dec. 31, 2020					27,743,000
Balance at Dec. 31, 2020	740,047	$ 21,058	586,909	632,549	$ (416,402)	(58,951)	(25,116)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	17,112			17,112
Dividend	(3,217)			(3,217)
Amortization of deferred compensation	609						609
Equity awards granted, net (in shares)		194,000
Equity awards granted, net	0	$ 48	(48)
ESOP allocation of common stock	756		756
Stock-based compensation	4,349		4,349
Other comprehensive income, net of tax	4,775					4,775
Ending balance (in shares) at Mar. 31, 2021		84,427,000
Ending balance (in shares) at Mar. 31, 2021					27,743,000
Balance at Mar. 31, 2021	764,431	$ 21,106	591,966	646,444	$ (416,402)	(54,176)	(24,507)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,707			16,707
Dividend	(4,546)			(4,546)
Amortization of deferred compensation	610						610
Equity awards granted, net (in shares)		(7,000)
Equity awards granted, net	0	$ (2)	2
ESOP allocation of common stock	856		856
Stock-based compensation	4,544		4,544
Other comprehensive income, net of tax	2,739					2,739
Ending balance (in shares) at Jun. 30, 2021		84,420,000
Ending balance (in shares) at Jun. 30, 2021					27,743,000
Balance at Jun. 30, 2021	785,341	$ 21,104	597,368	658,605	$ (416,402)	(51,437)	(23,897)
Beginning balance (in shares) at Sep. 30, 2021		84,375,000
Beginning balance (in shares) at Sep. 30, 2021					27,762,000
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)					422,000
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)		113,000			0
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)
Ending balance (in shares) at Dec. 31, 2021		84,488,000
Ending balance (in shares) at Dec. 31, 2021					28,184,000
Balance at Dec. 31, 2021	812,385	$ 21,122	605,867	684,557	$ (427,736)	(48,728)	(22,697)
Beginning balance (in shares) at Sep. 30, 2021		84,375,000
Beginning balance (in shares) at Sep. 30, 2021					27,762,000
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	225,274
Other comprehensive income, net of tax	(11,979)
Ending balance (in shares) at Jun. 30, 2022		84,746,000
Ending balance (in shares) at Jun. 30, 2022					27,682,000
Balance at Jun. 30, 2022	906,315	$ 21,187	609,027	775,694	$ (420,122)	(57,956)	(21,515)
Beginning balance (in shares) at Dec. 31, 2021		84,488,000
Beginning balance (in shares) at Dec. 31, 2021					28,184,000
Balance at Dec. 31, 2021	812,385	$ 21,122	605,867	684,557	$ (427,736)	(48,728)	(22,697)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	65,689			65,689
Dividend	(5,352)			(5,352)
Amortization of deferred compensation	591						591
Equity awards granted, net (in shares)		258,000			(470,000)
Equity awards granted, net	0	$ 65	(7,195)		$ 7,130
ESOP allocation of common stock	638		638
Stock-based compensation	4,314		4,314
Other comprehensive income, net of tax	4,949					4,949
Ending balance (in shares) at Mar. 31, 2022		84,746,000
Ending balance (in shares) at Mar. 31, 2022					27,714,000
Balance at Mar. 31, 2022	883,214	$ 21,187	603,624	744,894	$ (420,606)	(43,779)	(22,106)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	140,287			140,287
Dividend	(109,487)			(109,487)
Amortization of deferred compensation	591						591
Equity awards granted, net (in shares)		0			(32,000)
Equity awards granted, net	0	$ 0	(484)		$ 484
ESOP allocation of common stock	757		757
Stock-based compensation	5,130		5,130
Other comprehensive income, net of tax	(14,177)					(14,177)
Ending balance (in shares) at Jun. 30, 2022		84,746,000
Ending balance (in shares) at Jun. 30, 2022					27,682,000
Balance at Jun. 30, 2022	$ 906,315	$ 21,187	$ 609,027	$ 775,694	$ (420,122)	$ (57,956)	$ (21,515)