Changes in Accumulated Other Comprehensive Income (Loss) (Changes by Component)(Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated comprehensive loss at January 1, 2012	$ (134,516)	$ (75,938)
Other comprehensive income before reclassifications	207,197	48,577
Amounts reclassified from accumulated other comprehensive loss	(67,010)	(107,155)
Total other comprehensive income (loss)	140,187	(58,578)	(101,004)
Accumulated comprehensive loss at January 1, 2013	5,671	(134,516)	(75,938)
Changes related to cash flow derivative hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated comprehensive loss at January 1, 2012	(84,505)	(33,258)
Other comprehensive income before reclassifications	197,428	58,138
Amounts reclassified from accumulated other comprehensive loss	(69,599)	(109,385)
Total other comprehensive income (loss)	127,829	(51,247)
Accumulated comprehensive loss at January 1, 2013	43,324	(84,505)
Changes in defined benefit plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated comprehensive loss at January 1, 2012	(34,823)	(30,256)
Other comprehensive income before reclassifications	8,240	(6,797)
Amounts reclassified from accumulated other comprehensive loss	2,589	2,230
Total other comprehensive income (loss)	10,829	(4,567)
Accumulated comprehensive loss at January 1, 2013	(23,994)	(34,823)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated comprehensive loss at January 1, 2012	(15,188)	(12,424)
Other comprehensive income before reclassifications	1,529	(2,764)
Amounts reclassified from accumulated other comprehensive loss	0	0
Total other comprehensive income (loss)	1,529	(2,764)
Accumulated comprehensive loss at January 1, 2013	$ (13,659)	$ (15,188)