Summary Of Significant Accounting Policies (Schedule Of Basic And Diluted Earnings Per Share Calculations) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2010		Sep. 30, 2010		Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2010
Summary Of Significant Accounting Policies [Abstract]
Net income	$ 25,955		$ 18,222		$ 30,373	[1]	$ 21,258		$ 29,293	[2]	$ 19,441		$ 34,863	[3]	$ 22,767		$ 95,808		$ 106,364		$ 114,969
Net income available to participating securities																	(177)		(146)		(198)
Net income available to common shareholders																	$ 95,631		$ 106,218		$ 114,771
Weighted average common shares outstanding - basic																	27,233		27,664		28,144
Incremental share effect from:
Stock options																	0		0		3
Restricted stock																	4		5		6
Stock-settled stock appreciation rights																	28		20		21
Weighted average common shares outstanding - diluted																	27,265		27,689		28,174
Net Income Per Common Share:
Basic																	$ 3.51		$ 3.84		$ 4.08
Diluted	$ 0.95	[4]	$ 0.67	[4]	$ 1.11	[1],[4]	$ 0.78	[4]	$ 1.07	[2],[4]	$ 0.71	[4]	$ 1.25	[3],[4]	$ 0.81	[4]	$ 3.51	[4]	$ 3.84	[4]	$ 4.07

[1] Included in the second quarter earnings is income of approximately $1.8 million, net of taxes, or approximately $.06 per share, related to funds received under CDSOA.

[2] Included in the fourth quarter earnings is income of approximately $8.9 million, net of taxes, or approximately $.33 per share, related to additional funds received under CDSOA.

[3] Included in the second quarter earnings is income of approximately $0.6 million, net of taxes, or approximately $.02 per share, related to funds received under CDSOA.

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