Financial Instruments And Risk Management (Effect Of Derivative Instruments On The Condensed Consolidated Statements Of Operations, Derivatives In Fair Value Hedging Relationships) (Details) (Fair Value Hedging Relationships, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ (1,800)	$ 11,896
Amount of Gain or (Loss) Recognized in Earnings on Hedging Items	5,309	(8,825)
Interest expense | Interest rate swaps
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	(1,800)	11,896
Interest expense | 2018 Senior Notes
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Hedging Items	$ 5,309	$ (8,825)