Segment Information (Summary Of Inter-Segment Eliminations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenue, Net	$ 519,550	$ 395,328	$ 1,566,197	$ 1,156,611
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue, Net	(577)	(2)	(1,792)	(195)
Intersegment Eliminations [Member] | National Networks [Member]
Segment Reporting Information [Line Items]
Revenue, Net	(407)	0	(1,397)	(80)
Intersegment Eliminations [Member] | International And Other [Member]
Segment Reporting Information [Line Items]
Revenue, Net	$ (170)	$ (2)	$ (395)	$ (115)