Financial Instruments And Investments (Sale Of Securities And The Related Effects On Pre-Tax Income ) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Financial Instruments And Investments [Abstract]
Proceeds from sales of available-for-sale securities	$ 7,057	$ 14,582	$ 29,419	$ 74,095	$ 53,866	$ 89,180
Gross realized gains included in pre-tax income	212	447	593	1,526	814	1,757
Gross realized losses included in pre-tax income	(13)	(129)	(306)	(2,276)	(340)	(2,414)
Unrealized losses included in pre-tax income	0	0	0	(166)	(313)	(536)
Net gains (losses) in pre-tax income	199	318	287	(916)	161	(1,193)
Net unrealized holding gains (losses) included in accumulated other comprehensive income	4,300	6,169	8,861	11,986	6,802	18,470
Net gains (losses) in other comprehensive income	$ 4,101	$ 5,851	$ 8,574	$ 12,902	$ 6,641	$ 19,663