Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock Outstanding	Common Stock	Value of Shares Held in Rabbi Trust at Cost	Deferred Compensation and Other Retirement Benefit Obligations	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income/(Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding		47,349,778
Net income	$ 114,873						$ 114,873
Other comprehensive income	(111,647)							$ (111,647)
Cash dividends declared per common share (in dollars per share)							$ 1.02
Common dividend declared	(47,732)						$ (47,732)
Stock based compensation	2,466					$ 2,466
Restricted stock awards issued, net of awards surrendered		49,800
Restricted stock awards issued, net of awards surrendered	(1,085)		$ 0			(1,085)
Shares issued under direct stock purchase plan		14,176
Shares issued under direct stock purchase plan	1,159		0			1,159
Stock Repurchased During Period, Shares		(1,343,993)
Stock Repurchased During Period, Value	(105,298)		(13)			(105,285)
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits				$ (50)	$ 50
Increase (Decrease) in Deferred Compensation	0
Period End Balance at Jun. 30, 2022	2,871,185		459	(3,196)	3,196	2,146,333	833,857	(109,464)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding		47,377,125
Net income	61,776						$ 61,776
Other comprehensive income	(31,262)							(31,262)
Cash dividends declared per common share (in dollars per share)							$ 0.51
Common dividend declared	(23,570)						$ (23,570)
Stock based compensation	1,632					1,632
Restricted stock awards issued, net of awards surrendered		5,231
Restricted stock awards issued, net of awards surrendered	(22)					(22)
Shares issued under direct stock purchase plan		7,574
Shares issued under direct stock purchase plan	588					588
Stock Repurchased During Period, Shares		(1,320,169)
Stock Repurchased During Period, Value	(103,396)		(13)			(103,383)
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits				(17)	17
Increase (Decrease) in Deferred Compensation	0
Period End Balance at Jun. 30, 2022	$ 2,871,185		459	(3,196)	3,196	2,146,333	833,857	(109,464)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding		46,069,761
Common Stock, Shares, Outstanding	45,641,238	45,641,238
Net income	$ 123,891						$ 123,891
Other comprehensive income	10,149							10,149
Cash dividends declared per common share (in dollars per share)							$ 1.10
Common dividend declared	(48,598)						$ (48,598)
Proceeds from exercise of stock options, net of cash paid		1,666
Stock Repurchased During Period, Value, as a result of Stock Options Exercised	80					80
Stock based compensation	3,593					3,593
Restricted stock awards issued, net of awards surrendered		86,559
Restricted stock awards issued, net of awards surrendered	(1,110)		1			(1,111)
Shares issued under direct stock purchase plan		18,471
Shares issued under direct stock purchase plan	1,319					1,319
Stock Repurchased During Period, Shares		(1,617,033)
Stock Repurchased During Period, Value	(121,111)		(16)			(121,095)
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits				(62)	62
Increase (Decrease) in Deferred Compensation	0
Period End Balance at Jun. 30, 2023	2,854,914		440	(3,289)	3,289	1,997,674	1,009,735	(152,935)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding		44,114,827
Net income	62,644						$ 62,644
Other comprehensive income	(16,990)							(16,990)
Cash dividends declared per common share (in dollars per share)							$ 0.55
Common dividend declared	(24,247)						$ (24,247)
Stock based compensation	1,921					1,921
Restricted stock awards issued, net of awards surrendered		5,484
Restricted stock awards issued, net of awards surrendered	0		1			(1)
Shares issued under direct stock purchase plan		10,590
Shares issued under direct stock purchase plan	677					677
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits				(3)	3
Increase (Decrease) in Deferred Compensation	0
Period End Balance at Jun. 30, 2023	$ 2,854,914		$ 440	$ (3,289)	$ 3,289	$ 1,997,674	$ 1,009,735	$ (152,935)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding	44,130,901	44,130,901
Sales and Excise Tax Payable	$ 1,200