Restructuring (Restructuring and Related Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring (credit) expense	$ (81)	$ 389	$ 2,623	$ 354
National Networks [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring (credit) expense	(97)	37	(43)	67
International And Other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring (credit) expense	$ 16	$ 352	$ 2,666	$ 287