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				6 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Net income	$ 39,973	$ 37,592	$ 34,370	$ 30,655	$ 77,565	$ 65,025
Net income available to participating securities	(118)		(98)		(232)	(185)
Net income available to common shareholders	$ 39,855		$ 34,272		$ 77,333	$ 64,840
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average common shares outstanding - basic (in shares)	27,471		27,443		27,460	27,451
Weighted average common shares outstanding - diluted (in shares)	27,493		27,464		27,476	27,490
Net income per common share – basic	$ 1.45		$ 1.25		$ 2.82	$ 2.36
Net income per common share – diluted	$ 1.45		$ 1.25		$ 2.81	$ 2.36
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)	2		2		3	3
Stock Settled Stock Appreciation Rights SARS [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental share effect from stock-settled stock appreciation rights (in shares)	18		19		9	34
Weighted average number of antidilutive securities (in rights outstanding)	100		300		200	200
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental share effect from awards with forfeitable dividends (in shares)	2		0		4	2