Restructuring (Restructuring and Related Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring expense (credit)	$ 2,704	$ (35)
National Networks [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense (credit)	54	30
International And Other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense (credit)	$ 2,650	$ (65)