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																12 Months Ended
	Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017	[1]	Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017	[2]	Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2018		Jun. 30, 2017		Jun. 30, 2016
Accounting Policies [Abstract]
Net income	$ 32,387		$ 27,621		$ 45,920		$ 29,386		$ 28,487		$ 14,471		$ 38,956		$ 33,400		$ 135,314	[1]	$ 115,314	[2]	$ 121,764
Net income available to participating securities																	(271)		(196)		(242)
Net income available to common shareholders																	$ 135,043		$ 115,118		$ 121,522
Weighted average common shares outstanding - basic (in shares)																	27,403		27,376		27,336
Incremental share effect from:
Nonparticipating restricted stock (in shares)																	3		3		3
Stock-settled stock appreciation rights (in shares)																	53		61		34
Weighted average common shares outstanding - diluted (in shares)																	27,459		27,440		27,373
Net income per common share - basic (in dollars per share)																	$ 4.93		$ 4.21		$ 4.45
Net income per common share - diluted (in dollars per share)	$ 1.18	[3]	$ 1.00	[3]	$ 1.67	[3]	$ 1.07	[3]	$ 1.04	[3]	$ 0.53	[3]	$ 1.42	[3]	$ 1.22	[3]	$ 4.92	[1],[3]	$ 4.20	[2],[3]	$ 4.44

[1] Included in the second quarter net income was the one-time preliminary deferred tax benefit of $8.9 million, or approximately $0.32 per diluted share, resulting from the Tax Act. The fiscal year impact was $9.5 million, or approximately $0.35 per diluted share.

[2] Included in the third quarter and fiscal year net income was expense of $11.5 million, net of taxes, or approximately $0.42 per diluted share, related to a multiemployer pension settlement and other benefit-related costs.

[3] Diluted net income per common share amounts are calculated independently for each of the quarters presented. Accordingly, the sum of the quarterly net income per common share amounts may not agree with the fiscal year.