Capital and Financing Transactions Cash Flow Hedges (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Capital and Financing Transactions [Abstract]
Cash flow hedge loss to be reclassified during the next twelve months			$ 5,500,000
Accelerated loss reclassified into interest expense			386,000
Amount of gain (loss) recognized in other comprehensive income on derivative	5,992	274	6,481	(3,220)
Amount of gain (loss) reclassified from accumulated other comprehensive income into interest expense	(1,143)	(882)	(2,810)	(1,832)
Amount of gain (loss) recognized in income on derivative (ineffective portion, reclassifications of missed forecasted transactions and amounts excluded from effectiveness testing)	(386)	0	(386)	0
Fair value of derivatives in net liability position	10,100,000		10,100,000
Aggregate termination value	$ 10,100,000		$ 10,100,000