Description of Business and Basis of Presentation (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) network segment	Sep. 30, 2018 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | segment			2
Number of national programming networks | network			5
Program rights write-offs	$ 1,600	$ 11,400	$ 15,200	$ 20,600
Operating lease asset	172,575		172,575			$ 0
Present value of lease liabilities	$ 226,525		226,525
ASU No. 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease asset					$ 180,000
Deferred Rent Credit					57,000
Present value of lease liabilities					$ 237,000
Other related costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Program rights write-offs			$ 13,000