Condensed Statements of Shareholder's Equity Condensed Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Stock Options and Stock Appreciation Rights [ Member]	Additional Paid-in Capital [Member] Performance Shares [Member]	Additional Paid-in Capital [Member] Restricted Stock Units (RSUs) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Treasury Stock [Member] Stock Options and Stock Appreciation Rights [ Member]	Treasury Stock [Member] Performance Shares [Member]	Treasury Stock [Member] Restricted Stock Units (RSUs) [Member]	Total Accumulated Other Comprehensive Income (Loss) [Member]	Parent [Member]	Parent [Member] Stock Options and Stock Appreciation Rights [ Member]	Parent [Member] Performance Shares [Member]	Parent [Member] Restricted Stock Units (RSUs) [Member]
Beginning balance, shares at Jun. 30, 2017		39,041
Beginning balance at Jun. 30, 2017		$ 10,000	$ 164,655				$ 1,033,751	$ (381,448)				$ (81,702)	$ 745,256
Net income	$ 33,721												33,721
Other comprehensive (loss) income, net of tax												8,152	8,152
Cash dividends							(2)						(2)
Purchases of common stock for treasury, shares		(248)
Purchases of common stock for treasury								(13,761)					(13,761)
Exercise of stock appreciation rights and options, shares		1
Additional Paid in Capital, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units				$ (80)	$ (273)	$ (616)
Exercise of stock appreciation rights and options									$ 14
Performance share awards, shares		5
Performance share awards										$ (24)
Restricted stock units, shares		13
Restricted stock units											$ (57)
Total Shareholders' Equity, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units														$ (66)	$ (297)	$ (673)
Compensation expense			778	577									778	577
Other, shares		2
Other			(43)				3	23					(17)
Ending balance, shares at Sep. 30, 2017		38,814
Ending balance at Sep. 30, 2017		$ 10,000	164,998				1,067,473	(395,253)				(73,550)	773,668
Beginning balance, shares at Jun. 30, 2017		39,041
Beginning balance at Jun. 30, 2017		$ 10,000	164,655				1,033,751	(381,448)				(81,702)	745,256
Net income	101,263
Other comprehensive (loss) income, net of tax	1,702											1,702
Ending balance, shares at Mar. 31, 2018		38,696
Ending balance at Mar. 31, 2018		$ 10,000	167,848				1,112,136	(403,956)				(80,000)	806,028
Beginning balance, shares at Sep. 30, 2017		38,814
Beginning balance at Sep. 30, 2017		$ 10,000	164,998				1,067,473	(395,253)				(73,550)	773,668
Net income	30,950												30,950
Other comprehensive (loss) income, net of tax												(6,064)	(6,064)
Cash dividends							(11,246)						(11,246)
Purchases of common stock for treasury, shares		(145)
Purchases of common stock for treasury								(9,017)					(9,017)
Exercise of stock appreciation rights and options, shares		3
Additional Paid in Capital, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units				(171)		(54)
Exercise of stock appreciation rights and options									(26)
Restricted stock units, shares		2
Restricted stock units											8
Total Shareholders' Equity, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units														(197)		(46)
Compensation expense			799	436									799	436
Other							(21)						(21)
Ending balance, shares at Dec. 31, 2017		38,674
Ending balance at Dec. 31, 2017		$ 10,000	166,008				1,087,156	(404,288)				(79,614)	779,262
Net income	36,592												36,592
Other comprehensive (loss) income, net of tax	$ (386)											(386)	(386)
Cash dividends							(11,637)						(11,637)
Exercise of stock appreciation rights and options, shares		8
Additional Paid in Capital, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units				(169)
Exercise of stock appreciation rights and options									(18)
Restricted stock units											(3)
Total Shareholders' Equity, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units														(187)		(3)
Compensation expense			1,904	466									1,904	466
Other, shares		14
Other			(361)				25	353					17
Ending balance, shares at Mar. 31, 2018		38,696
Ending balance at Mar. 31, 2018		$ 10,000	167,848				1,112,136	(403,956)				(80,000)	806,028
Beginning balance, shares at Jun. 30, 2018	38,703	38,703
Beginning balance at Jun. 30, 2018	$ 814,963	$ 10,000	169,383				1,129,678	(403,875)				(90,223)	814,963
Net income	$ 48,938												48,938
Other comprehensive (loss) income, net of tax												5,347	5,347
Cumulative effect of adopting accounting standards | Adjustments for New Accounting Pronouncement [Member]							3,056						3,056
Cash dividends							(13)						(13)
Exercise of stock appreciation rights and options, shares		17
Additional Paid in Capital, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units				(855)	$ (844)	(760)
Exercise of stock appreciation rights and options									(210)
Performance share awards, shares		18
Performance share awards										$ (301)
Restricted stock units, shares		16
Restricted stock units											(198)
Total Shareholders' Equity, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units														(1,065)	$ (1,145)	(958)
Compensation expense			1,043	651									1,043	651
Other							24	(35)					(11)
Ending balance, shares at Sep. 30, 2018		38,754
Ending balance at Sep. 30, 2018		$ 10,000	168,618				1,181,683	(404,619)				(84,876)	870,806
Beginning balance, shares at Jun. 30, 2018	38,703	38,703
Beginning balance at Jun. 30, 2018	$ 814,963	$ 10,000	169,383				1,129,678	(403,875)				(90,223)	814,963
Net income	104,190
Other comprehensive (loss) income, net of tax	$ (6,771)											(6,771)
Ending balance, shares at Mar. 31, 2019	38,593	38,593
Ending balance at Mar. 31, 2019	$ 882,848	$ 10,000	171,734				1,213,314	(415,206)				(96,994)	882,848
Beginning balance, shares at Sep. 30, 2018		38,754
Beginning balance at Sep. 30, 2018		$ 10,000	168,618				1,181,683	(404,619)				(84,876)	870,806
Net income	38,717												38,717
Other comprehensive (loss) income, net of tax												(9,756)	(9,756)
Cash dividends							(11,651)						(11,651)
Additional Paid in Capital, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units				(7)		$ (140)
Exercise of stock appreciation rights and options									1
Restricted stock units, shares		3
Restricted stock units											$ 31
Total Shareholders' Equity, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units														(6)		$ (109)
Compensation expense			1,308	606									1,308	606
Other							(1)	1					0
Ending balance, shares at Dec. 31, 2018		38,757
Ending balance at Dec. 31, 2018		$ 10,000	170,385				1,208,748	(404,586)				(94,632)	889,915
Net income	16,535												16,535
Other comprehensive (loss) income, net of tax	$ (2,362)											(2,362)	(2,362)
Cash dividends							(11,979)						(11,979)
Purchases of common stock for treasury, shares		(192)
Purchases of common stock for treasury								(11,158)					(11,158)
Exercise of stock appreciation rights and options, shares		13
Additional Paid in Capital, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units				(197)
Exercise of stock appreciation rights and options									$ 149
Total Shareholders' Equity, Exercise of stock appreciation rights and options, Performance share awards, Restricted stock units														(48)
Compensation expense			1,365	$ 574									1,365	$ 574
Other, shares		15
Other			(393)				10	389					6
Ending balance, shares at Mar. 31, 2019	38,593	38,593
Ending balance at Mar. 31, 2019	$ 882,848	$ 10,000	$ 171,734				$ 1,213,314	$ (415,206)				$ (96,994)	$ 882,848