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, 2018		27,488,000
Balance at Jun. 30, 2018	$ 652,282	$ 119,232	$ 1,279,343	$ (8,259)	$ (738,034)
Net income	150,549		150,549
Net pension and postretirement benefit gains (losses), net of tax effect	(2,049)			(2,049)
Cash dividends - common stock	(70,110)		(70,110)
Purchase of treasury stock (in shares)		(48,000)
Purchase of treasury stock	(7,411)				(7,411)
Stock-based plans (in shares)		51,000
Stock-based plans	(2,360)	$ (2,360)
Stock-based compensation expense	5,972	$ 5,972
Balance (in shares) at Jun. 30, 2019		27,491,000
Balance at Jun. 30, 2019	726,873	$ 122,844	1,359,782	(10,308)	(745,445)
Net income	136,983		136,983
Net pension and postretirement benefit gains (losses), net of tax effect	(1,762)			(1,762)
Cash dividends - common stock	(75,644)		(75,644)
Purchase of treasury stock (in shares)		(38,000)
Purchase of treasury stock	(5,459)				(5,459)
Stock-based plans (in shares)		71,000
Stock-based plans	(3,806)	$ (3,806)
Stock-based compensation expense	$ 6,115	$ 6,115
Balance (in shares) at Jun. 30, 2020	27,523,935	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	27,531,040	27,531,000
Balance at Jun. 30, 2021	$ 843,147	$ 128,617	$ 1,482,220	$ (8,253)	$ (759,437)