Comprehensive Income/Loss (Details1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance			$ (4,526)	$ (4,486)
Net change in other comprehensive income (loss)	(2,928)	(502)	(2,871)	156
Ending Balance	(7,397)	(4,330)	(7,397)	(4,330)
Deferred Gain on Hedge Transactions [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance			859	1,004
Net change in other comprehensive income (loss)			(72)	(73)
Ending Balance	787	931	787	931
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance			5,478	6,574
Net change in other comprehensive income (loss)			(5,368)	(255)
Ending Balance	110	6,319	110	6,319
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance			(9,577)	(10,804)
Net change in other comprehensive income (loss)			2,526	438
Ending Balance	(7,051)	(10,366)	(7,051)	(10,366)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Rollforward]
Beginning Balance			(1,286)	(1,260)
Net change in other comprehensive income (loss)			43	46
Ending Balance	$ (1,243)	$ (1,214)	$ (1,243)	$ (1,214)