QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 1,622	$ 1,125	$ 771	$ 722	$ 894	$ 766	$ 730	$ 665	$ 4,240	$ 3,055	$ 2,636
Operating income (loss)	277	(6)	106	93	263	158	132	107	470	660	737
Net income (loss)	88	(49)	43	23	208	65	29	44	105	346	594
Net income (loss) attributable to Sinclair Broadcast Group	$ 44	$ (60)	$ 42	$ 21	$ 206	$ 64	$ 28	$ 43	$ 47	$ 341	$ 576
Basic earnings per share common shares (in dollars per share)	$ 0.47	$ (0.65)	$ 0.46	$ 0.23	$ 2.12	$ 0.63	$ 0.27	$ 0.42	$ 0.52	$ 3.38	$ 5.77
Diluted earnings per share common shares (in dollars per share)	$ 0.47	$ (0.64)	$ 0.45	$ 0.23	$ 2.10	$ 0.62	$ 0.27	$ 0.42	$ 0.51	$ 3.35	$ 5.72