Comprehensive Income/Loss (Comprised of the following Components) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance	$ (7,434)	$ (4,526)
Net change in other comprehensive income	2,380	57
Ending Balance	(5,054)	(4,469)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance	(2,023)	5,478
Net change in other comprehensive income	1,917	(777)
Ending Balance	(106)	4,701
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance	(5,698)	(9,577)
Net change in other comprehensive income	539	869
Ending Balance	(5,159)	(8,708)
Deferred Gain on Hedge Transactions [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance	715	859
Net change in other comprehensive income	(37)	(36)
Ending Balance	678	823
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance	(428)	(1,286)
Net change in other comprehensive income	(39)	1
Ending Balance	$ (467)	$ (1,285)