Acquisitions - Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Nov. 30, 2018	Dec. 31, 2017	Oct. 02, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair values of the assets acquired and the liabilities assumed
Other current assets	$ 28,899		$ 21,998
Property and equipment	237,927		209,995
Current portion of programming	39,016		53,468
Goodwill	834,013		755,949		$ 575,780	$ 544,787
Programming (less current portion)	70,749		85,269
Accounts payable	(26,919)		(23,647)
Accrued expenses	(46,112)		(44,396)
Other current liabilities	(25,339)		(10,085)
Deferred tax liabilities, net, noncurrent	(25,531)		0
Current portion of programming liabilities	(40,301)		(58,176)
Programming liabilities	$ (43,825)		$ (54,641)
Triton Digital Canada, Inc.
Fair values of the assets acquired and the liabilities assumed
Cash		$ 10,515
Accounts receivable		8,650
Other current assets		679
Property and equipment		705
Goodwill		83,876
Intangible assets		75,000
Accounts payable		(1,881)
Accrued expenses		(2,964)
Other current liabilities		(19)
Deferred tax liabilities, net, noncurrent		(14,577)
Net purchase price		$ 159,984
Katz Broadcasting Group
Fair values of the assets acquired and the liabilities assumed
Cash				$ 21,372
Accounts receivable				44,306
Current portion of programming				36,218
Goodwill				203,760
Intangible assets				32,300
Programming (less current portion)				52,908
Other long-term assets				11,356
Accounts payable and accrued liabilities				(29,339)
Current portion of programming liabilities				(32,877)
Programming liabilities				(37,692)
Net purchase price				$ 302,312