Capital and Financing Transactions Cash Flow Hedges (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Capital and Financing Transactions [Abstract]
Amount of gain (loss) recognized in other comprehensive income on derivative	$ (1,533,000)	$ (7,413,000)
Amount of gain (loss) reclassified from accumulated other comprehensive income into interest expense	(1,453,000)	(3,902,000)
Fair value of derivatives in net liability position	8,200,000
Aggregate termination value	$ 8,200,000