Financial Instruments And Risk Management (Effect Of Derivative Instruments On The Condensed Consolidated Statements Of Operations Derivatives In Fair Value Hedging Relationships) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ 11,896	$ (6,328)
Amount of Gain or (Loss) Recognized in Earnings on Hedged Items	(8,825)	6,328
Interest Expense [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	11,896	(6,328)
Interest Expense [Member] | 2018 Senior Notes [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Hedged Items	$ (8,825)	$ 6,328