QUARTERLY FINANCIAL INFORMATION (UNAUDITED): (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Total revenues, net	$ 613,818	$ 494,956	$ 455,136	$ 412,648	$ 427,715	$ 338,644	$ 314,154	$ 282,618	$ 1,976,558	$ 1,363,131	$ 1,061,679
Operating income	208,949	101,663	103,039	81,000	103,286	72,798	84,280	63,656	494,651	324,020	329,285
Income from continuing operations	97,089	48,768	41,601	27,657	4,237	30,551	12,956	16,515	215,115	64,259	144,488
Income from discontinued operations						6,100	5,103	355		11,558	465
Net income attributable to Sinclair Broadcast Group	$ 95,445	$ 48,341	$ 41,335	$ 27,158	$ 2,303	$ 36,342	$ 17,826	$ 16,997	$ 212,279	$ 73,468	$ 144,666
Basic earnings per common share from continuing operations attributable to Sinclair Broadcast Group (in dollars per share)	$ 0.99	$ 0.50	$ 0.43	$ 0.27	$ 0.02	$ 0.30	$ 0.14	$ 0.20	$ 2.19	$ 0.66	$ 1.78
Basic earnings per common share attributable to Sinclair Broadcast Group (in dollars per share)	$ 0.99	$ 0.50	$ 0.43	$ 0.27	$ 0.02	$ 0.37	$ 0.19	$ 0.21	$ 2.19	$ 0.79	$ 1.79
Diluted earnings per common share from continuing operations attributable to Sinclair Broadcast Group (in dollars per share)	$ 0.98	$ 0.49	$ 0.42	$ 0.27	$ 0.02	$ 0.30	$ 0.14	$ 0.20	$ 2.17	$ 0.66	$ 1.78
Diluted earnings per common share attributable to Sinclair Broadcast Group (in dollars per share)	$ 0.98	$ 0.49	$ 0.42	$ 0.27	$ 0.02	$ 0.36	$ 0.19	$ 0.21	$ 2.17	$ 0.78	$ 1.78