Changes in Operations and Non-operating Items Severance by Business Segment (Details) - Employee Severance - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Severance Costs	$ 4,739	$ 10,406	$ 5,276
Operating Segments | Television and Entertainment
Restructuring Cost and Reserve [Line Items]
Severance Costs	4,367	9,228	2,317
Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Severance Costs	$ 372	$ 1,178	$ 2,959