Reclassifications From Accumulated Other Comprehensive Income (Components of AOCI And Related Tax Effects) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Beginning balance	$ 149,804
Other comprehensive income before reclassification	(46,510)
Amounts reclassified from accumulated other comprehensive income	(47,687)	[1]
Net current period other comprehensive income	(94,197)
Ending balance	55,607
Gains and Losses on Cash Flow Hedges [Member]
Beginning balance	172,166
Other comprehensive income before reclassification	(45,481)
Amounts reclassified from accumulated other comprehensive income	(47,954)	[1]
Net current period other comprehensive income	(93,435)
Ending balance	78,731
Pension and Other Postretirement [Member]
Beginning balance	(22,311)
Amounts reclassified from accumulated other comprehensive income	267	[1]
Net current period other comprehensive income	267
Ending balance	(22,044)
Foreign Currency [Member]
Beginning balance	(51)
Other comprehensive income before reclassification	(1,029)
Net current period other comprehensive income	(1,029)
Ending balance	$ (1,080)

[1] See separate table below for details about these reclassifications.