Restructuring and Other Related Charges (Summary of Restructuring and Other Related Charges by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Total restructuring and other related charges	$ 10,191	$ 3,139	$ 29,995	$ 3,139
Operating segments | National Networks
Restructuring Cost and Reserve [Line Items]
Total restructuring and other related charges	6,199	0	6,776
Operating segments | International and Other
Restructuring Cost and Reserve [Line Items]
Total restructuring and other related charges	3,992	3,139	23,915	3,139
Inter-segment eliminations
Restructuring Cost and Reserve [Line Items]
Total restructuring and other related charges	$ 0	$ 0	$ (696)	$ 0