Segment Information (Summary Of Inter-Segment Eliminations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Revenue, Net	$ 379,322	$ 327,570	$ 761,283	$ 653,809
National Networks [Member]
Segment Reporting Information [Line Items]
Revenue, Net	353,568	305,184	713,034	609,407
International And Other [Member]
Segment Reporting Information [Line Items]
Revenue, Net	29,919	26,269	56,212	52,615
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue, Net	(4,165)	(3,883)	(7,963)	(8,213)
Intersegment Eliminations [Member] | National Networks [Member]
Segment Reporting Information [Line Items]
Revenue, Net	(61)	(201)	(184)	(504)
Intersegment Eliminations [Member] | International And Other [Member]
Segment Reporting Information [Line Items]
Revenue, Net	$ (4,104)	$ (3,682)	$ (7,779)	$ (7,709)