Condensed 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, 2021		27,531,000
Balance at Jun. 30, 2021	$ 843,147	$ 128,617	$ 1,482,220	$ (8,253)	$ (759,437)
Net income	30,655		30,655
Net pension and postretirement benefit gains, net of tax effect	42			42
Cash dividends - common stock	(20,675)		(20,675)
Purchase of treasury stock (in shares)		(30,000)
Purchase of treasury stock	(5,329)				(5,329)
Stock-based plans (in shares)		29,000
Stock-based plans	(59)	$ (59)
Stock-based compensation expense	2,274	$ 2,274
Balance (in shares) at Sep. 30, 2021		27,530,000
Balance at Sep. 30, 2021	$ 850,055	$ 130,832	1,492,200	(8,211)	(764,766)
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	37,592		37,592
Net pension and postretirement benefit gains, net of tax effect	95			95
Cash dividends - common stock	(22,067)		(22,067)
Purchase of treasury stock (in shares)		0
Purchase of treasury stock	(84)				(84)
Stock-based plans (in shares)		34,000
Stock-based plans	(617)	$ (617)
Stock-based compensation expense	$ 2,465	$ 2,465
Balance (in shares) at Sep. 30, 2022	27,553,752	27,554,000
Balance at Sep. 30, 2022	$ 862,071	$ 139,662	$ 1,500,570	$ (11,077)	$ (767,084)