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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ 5,354	$ 13,050	$ (4,492)	$ 26,509
Amount of (Loss) or Gain Recognized in Earnings on Hedged Items	(1,536)	(9,823)	15,164	(16,897)
Interest expense | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	5,354	13,050	(4,492)	26,509
Interest expense | 2016 Senior Notes
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) or Gain Recognized in Earnings on Hedged Items	(1,747)		833
Interest expense | 2018 Senior Notes (6.00% coupon)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) or Gain Recognized in Earnings on Hedged Items	$ 211	$ (9,823)	$ 14,331	$ (16,897)