Segment Information (Summary Of Inter-Segment Eliminations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Revenue, Net	$ 522,093	$ 379,322	$ 1,046,647	$ 761,283
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue, Net	(511)	(62)	(1,215)	(193)
Intersegment Eliminations [Member] | National Networks [Member]
Segment Reporting Information [Line Items]
Revenue, Net	(316)	(80)	(990)	(80)
Intersegment Eliminations [Member] | International And Other [Member]
Segment Reporting Information [Line Items]
Revenue, Net	$ (195)	$ 18	$ (225)	$ (113)