Recently Adopted Standards and Issued Accounting Standards (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019	Dec. 31, 2015
Statement [Line items]
Total operating revenues	$ 368,113	$ 302,726	$ 283,395	$ 254,191	$ 261,746	$ 200,509	$ 216,242	$ 198,475	$ 1,208,425	$ 876,972	$ 874,451
Employee compensation and benefits									394,029	367,735	343,570
Programming									350,753	228,605	172,617
Other expenses									246,487	185,869	173,797
Restructuring costs									8,911	4,422	0
Acquisition and related integration costs									4,124	0	578
Total costs and expenses	281,628	$ 247,304	$ 245,610	$ 238,682	228,938	$ 189,184	$ 184,095	$ 184,414	1,013,224	786,631	690,562
Unrecognized tax benefits	$ 1,112				$ 1,088				$ 1,112	1,088	2,665		$ 5,011
Reclassification of tax effects from AOCI to retained earnings										(19,370)
Share Based Compensation Arrangements | Deferred Tax Asset
Statement [Line items]
Unrecognized tax benefits													$ 14,700
AOCI
Statement [Line items]
Reclassification of tax effects from AOCI to retained earnings										19,370
AOCI | Accounting Standards Update 2018-02
Statement [Line items]
Reclassification of tax effects from AOCI to retained earnings										19,400
Advertising contracts | Customer Concentration Risk
Statement [Line items]
Concentration risk, percentage									69.00%
Retransmission revenue | Customer Concentration Risk
Statement [Line items]
Concentration risk, percentage									25.00%
As previously reported
Statement [Line items]
Total operating revenues										864,834	868,820
Employee compensation and benefits										367,735	343,570
Programming										216,467	166,986
Other expenses										185,869	173,797
Restructuring costs										4,422
Acquisition and related integration costs											578
Total costs and expenses										774,493	684,931
Adjustments for adoption of new revenue standard | Accounting Standards Update 2014-09
Statement [Line items]
Total operating revenues										12,138	5,631
Employee compensation and benefits										0	0
Programming										12,138	5,631
Other expenses										0	0
Restructuring costs										0
Acquisition and related integration costs											0
Total costs and expenses										12,138	5,631
Advertising
Statement [Line items]
Total operating revenues									$ 836,049	563,879	608,748
Advertising | As previously reported
Statement [Line items]
Total operating revenues										564,708	609,612
Advertising | Adjustments for adoption of new revenue standard | Accounting Standards Update 2014-09
Statement [Line items]
Total operating revenues										(829)	(864)
Retransmission and carriage
Statement [Line items]
Total operating revenues									304,402	259,712	220,723
Retransmission and carriage | As previously reported
Statement [Line items]
Total operating revenues										259,712	220,723
Retransmission and carriage | Adjustments for adoption of new revenue standard | Accounting Standards Update 2014-09
Statement [Line items]
Total operating revenues										0	0
Other
Statement [Line items]
Total operating revenues									$ 67,974	53,381	44,980
Other | As previously reported
Statement [Line items]
Total operating revenues										40,414	38,485
Other | Adjustments for adoption of new revenue standard | Accounting Standards Update 2014-09
Statement [Line items]
Total operating revenues										$ 12,967	$ 6,495
Subsequent Event
Statement [Line items]
Right-of-use asset												$ 50,000
Lease liabilities												$ 50,000