Capital and Financing Transactions Cash Flow Hedges (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Capital and Financing Transactions [Abstract]
Cash flow hedge loss to be reclassified during the next twelve months			$ 5,600,000
Amount of gain (loss) recognized in other comprehensive income on derivative	(3,171,000)	(2,348,000)	3,310,000	(7,037,000)
Amount of gain (loss) reclassified from accumulated other comprehensive income into interest expense	(1,393,000)	(992,000)	(4,203,000)	(2,504,000)
Amount of gain (loss) recognized in income on derivative (ineffective portion, reclassifications of missed forecasted transactions and amounts excluded from effectiveness testing)	(67,000)	0	(454,000)	0
Fair value of derivatives in net liability position	10,100,000		10,100,000
Aggregate termination value	$ 10,100,000		$ 10,100,000