Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock Outstanding [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]
Balance (in shares) at Jun. 30, 2020		27,524,000
Balance at Jun. 30, 2020	$ 783,300	$ 125,153	$ 1,421,121	$ (12,070)	$ (750,904)
Net income	142,332		142,332
Net pension and postretirement benefit gains (losses), net of tax effect	3,817			3,817
Cash dividends - common stock	(81,233)		(81,233)
Purchase of treasury stock (in shares)		(46,000)
Purchase of treasury stock	(8,533)				(8,533)
Stock-based plans (in shares)		53,000
Stock-based plans	(3,662)	$ (3,662)
Stock-based compensation expense	7,126	$ 7,126
Balance (in shares) at Jun. 30, 2021		27,531,000
Balance at Jun. 30, 2021	843,147	$ 128,617	1,482,220	(8,253)	(759,437)
Net income	89,586		89,586
Net pension and postretirement benefit gains (losses), net of tax effect	(2,919)			(2,919)
Cash dividends - common stock	(86,761)		(86,761)
Purchase of treasury stock (in shares)		(45,000)
Purchase of treasury stock	(7,563)				(7,563)
Stock-based plans (in shares)		34,000
Stock-based plans	(366)	$ (366)
Stock-based compensation expense	$ 9,563	$ 9,563
Balance (in shares) at Jun. 30, 2022	27,520,237	27,520,000
Balance at Jun. 30, 2022	$ 844,687	$ 137,814	1,485,045	(11,172)	(767,000)
Net income	111,286		111,286
Net pension and postretirement benefit gains (losses), net of tax effect	1,807			1,807
Cash dividends - common stock	(92,368)		(92,368)
Purchase of treasury stock (in shares)		(48,000)
Purchase of treasury stock	(9,201)				(9,201)
Stock-based plans (in shares)		56,000
Stock-based plans	(3,026)	$ (3,026)
Stock-based compensation expense	$ 9,082	$ 9,082
Balance (in shares) at Jun. 30, 2023	27,527,550	27,528,000
Balance at Jun. 30, 2023	$ 862,267	$ 143,870	$ 1,503,963	$ (9,365)	$ (776,201)