Summary Of Significant Accounting Policies (Schedule Of Basic And Diluted Net Income Per Common Share Calculations) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Mar. 31, 2022	Mar. 31, 2021
Accounting Policies [Abstract]
Net income (loss)	$ (4,483)	$ 34,370	$ 30,655	$ 28,897	$ 44,630	$ 37,079	$ 60,542	$ 110,606
Net income available to participating securities	(52)			(56)			(168)	(223)
Net (loss) income available to common shareholders	$ (4,535)			$ 28,841			$ 60,374	$ 110,383
Weighted average common shares outstanding - basic (in shares)	27,442			27,483			27,448	27,474
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental share effect from stock-settled stock appreciation rights (in shares)	0			41			26	37
Weighted average common shares outstanding - diluted (in shares)	27,442			27,526			27,478	27,513
Net (loss) income per common share – basic	$ (0.17)			$ 1.05			$ 2.20	$ 4.02
Net (loss) income per common share – diluted	$ (0.17)			$ 1.05			$ 2.20	$ 4.01
Nonparticipating restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental share effect from awards with forfeitable dividends (in shares)	0			2			3	2
Performance units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental share effect from awards with forfeitable dividends (in shares)	0			0			1	0