QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Revenues, net	$ 1,476	$ 1,535	$ 1,612	$ 1,511	$ 1,512	$ 1,539	$ 1,283	$ 1,609	$ 6,134	$ 5,943	$ 4,240
Operating income (loss)	165	73	(178)	35	625	(4,216)	492	327	95	(2,772)	470
Net income (loss)	(41)	17	(328)	26	514	(3,367)	273	151
Net (loss) income attributable to Sinclair Broadcast Group	$ (89)	$ 19	$ (332)	$ (12)	$ 467	$ (3,256)	$ 252	$ 123	$ (414)	$ (2,414)	$ 47
Basic earnings (loss) per common share (in dollars per share)	$ (1.18)	$ 0.25	$ (4.41)	$ (0.16)	$ 6.32	$ (43.53)	$ 3.13	$ 1.36	$ (5.51)	$ (30.20)	$ 0.52
Diluted earnings (loss) per common share (in dollars per share)	$ (1.18)	$ 0.25	$ (4.41)	$ (0.16)	$ 6.27	$ (43.53)	$ 3.12	$ 1.35	$ (5.51)	$ (30.20)	$ 0.51