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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ (8,046)	$ 1,564	$ (9,846)	$ 13,459
Amount of Gain or (Loss) Recognized in Earnings on Hedged Items	11,391	1,751	16,700	(7,074)
Interest expense | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	(8,046)	1,564	(9,846)	13,459
Interest expense | 2016 Senior Notes
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Hedged Items	2,580		2,580
Interest expense | 2018 Senior Notes (6.00% coupon)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Hedged Items	$ 8,811	$ 1,751	$ 14,120	$ (7,074)