Summary Of Significant Accounting Policies (Schedule Of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
(Increase) Decrease In Accumulated Other Comprehensive (Income) Loss [Roll Forward]
Beginning balance	$ 4,202		$ 24,743
Change excluding amounts reclassified from accumulated other comprehensive loss	(94)		2,107
Amounts reclassified from accumulated other comprehensive loss	(487)		(1,021)
Net other comprehensive (income) loss	(581)		1,086
Ending balance	3,621		25,829
Gain On Investments [Member]
(Increase) Decrease In Accumulated Other Comprehensive (Income) Loss [Roll Forward]
Beginning balance	(340)
Change excluding amounts reclassified from accumulated other comprehensive loss	(57)
Amounts reclassified from accumulated other comprehensive loss	38	[1]
Net other comprehensive (income) loss	(19)
Ending balance	(359)		0
(Gain) Loss On Cash Flow Hedges [Member]
(Increase) Decrease In Accumulated Other Comprehensive (Income) Loss [Roll Forward]
Beginning balance	(1,233)		7,489
Change excluding amounts reclassified from accumulated other comprehensive loss	(37)		2,107
Amounts reclassified from accumulated other comprehensive loss	(473)	[2]	(656)	[2]
Net other comprehensive (income) loss	(510)		1,451
Ending balance	(1,743)		8,940
Defined Benefit Pension Plan [Member]
(Increase) Decrease In Accumulated Other Comprehensive (Income) Loss [Roll Forward]
Beginning balance	5,775		17,254
Change excluding amounts reclassified from accumulated other comprehensive loss	0		0
Amounts reclassified from accumulated other comprehensive loss	(52)	[3]	(365)	[3]
Net other comprehensive (income) loss	(52)		(365)
Ending balance	$ 5,723		$ 16,889

[1] This reclassification component is included in interest and other income.

[2] This reclassification component is included in interest expense (see Note 7 for additional information).

[3] This reclassification component is included in the computation of net periodic benefit cost (see Note 13 for additional information).