Stockholders' Equity (Schedule Of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net, beginning balance	$ (105,085)		$ (83,902)		$ (65,053)
Other comprehensive income (loss) before reclassification	6,260		(46,984)		(42,526)
Amounts reclassified from accumulated other comprehensive loss, net	25,871		25,801		23,677
Accumulated other comprehensive loss, net, ending balance	(72,954)		(105,085)		(83,902)
Accumulated other comprehensive loss, tax benefit	10,829		27,413		12,602		1,383
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net, beginning balance	(24,634)		(27,135)		(26,569)
Other comprehensive income (loss) before reclassification	6,198		2,501		(566)
Accumulated other comprehensive loss, net, ending balance	(18,436)		(24,634)		(27,135)
Unrealized losses on interest rate swap contracts [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net, beginning balance	(80,451)	[1]	(56,767)	[1]	(38,484)	[1]
Other comprehensive income (loss) before reclassification	62	[2]	(49,485)	[3]	(41,960)	[4]
Amounts reclassified from accumulated other comprehensive loss, net	25,871	[2]	25,801	[3]	23,677	[4]
Accumulated other comprehensive loss, net, ending balance	(54,518)	[1]	(80,451)	[1]	(56,767)	[1]
Other comprehensive loss before reclassification - interest rate swap contracts, tax expense (benefit)	40		(30,946)		(25,748)
Amounts reclassified from AOCI - interest rate swap contracts, tax expense	$ 16,544		$ 16,135		$ 14,529

[1] Net of deferred income tax benefit of $1,383 as of January 1, 2011, and $12,602, $27,413, and $10,829 as of December 31, 2011, 2012, and 2013, respectively.

[2] Net of deferred income tax expense of $40 for Other comprehensive income before reclassification and deferred income tax expense of $16,544 for Amounts reclassified from accumulated other comprehensive loss, net, respectively, for the year ended December 31, 2013.

[3] Net of deferred income tax benefit of $30,946 for Other comprehensive income before reclassification and deferred income tax expense of $16,135 for Amounts reclassified from accumulated other comprehensive loss, net, for the year ended December 31, 2012.

[4] Net of deferred income tax benefit of $25,748 for Other comprehensive income before reclassification and deferred income tax expense of $14,529 for Amounts reclassified from accumulated other comprehensive loss, net, for the year ended December 31, 2011.