CONDENSED CONSOLIDATED FINANCIAL STATEMENTS - Statement of Operations and Comprehensive Income (Details) - USD ($) $ 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
Condensed Financial Statements, Captions [Line Items]
Revenue	$ 1,622	$ 1,125	$ 771	$ 722	$ 894	$ 766	$ 730	$ 665	$ 4,240	$ 3,055	$ 2,636
Media programming and production expenses									2,073	1,191	1,064
Selling, general and administrative									1,119	741	647
Depreciation, amortization and other operating expenses									578	463	188
Total operating expenses									3,770	2,395	1,899
Operating Income (Loss)	277	(6)	106	93	263	158	132	107	470	660	737
Equity in earnings of consolidated subsidiaries									0	0	0
Interest expense									(422)	(292)	(212)
Other income (expense)									(39)	(58)	(6)
Total other expense, net									(461)	(350)	(218)
Income tax benefit (provision)									96	36	75
NET INCOME									105	346	594
Net income attributable to the redeemable noncontrolling interests									(48)	0	0
Net income attributable to the noncontrolling interests									(10)	(5)	(18)
Net income (loss) attributable to Sinclair Broadcast Group	$ 44	$ (60)	$ 42	$ 21	$ 206	$ 64	$ 28	$ 43	47	341	576
Comprehensive income (loss)									104	347	593
Reportable legal entities | Sinclair Broadcast Group, Inc.
Condensed Financial Statements, Captions [Line Items]
Revenue									0	0	0
Media programming and production expenses									0	0	0
Selling, general and administrative									147	10	9
Depreciation, amortization and other operating expenses									0	0	1
Total operating expenses									147	10	10
Operating Income (Loss)									(147)	(10)	(10)
Equity in earnings of consolidated subsidiaries									165	348	579
Interest expense									(5)	0	0
Other income (expense)									2	2	2
Total other expense, net									162	350	581
Income tax benefit (provision)									32	2	5
NET INCOME									47	342	576
Net income attributable to the redeemable noncontrolling interests									0
Net income attributable to the noncontrolling interests									0	0	0
Net income (loss) attributable to Sinclair Broadcast Group									47	342	576
Comprehensive income (loss)									47	347	593
Reportable legal entities | Sinclair Television Group, Inc.
Condensed Financial Statements, Captions [Line Items]
Revenue									35	0	0
Media programming and production expenses									0	0	0
Selling, general and administrative									147	100	103
Depreciation, amortization and other operating expenses									(20)	5	6
Total operating expenses									127	105	109
Operating Income (Loss)									(92)	(105)	(109)
Equity in earnings of consolidated subsidiaries									577	724	794
Interest expense									(216)	(285)	(205)
Other income (expense)									(7)	(2)	5
Total other expense, net									354	437	594
Income tax benefit (provision)									66	90	100
NET INCOME									328	422	585
Net income attributable to the redeemable noncontrolling interests									0
Net income attributable to the noncontrolling interests									0	0	0
Net income (loss) attributable to Sinclair Broadcast Group									328	422	585
Comprehensive income (loss)									327	422	584
Reportable legal entities | Guarantor Subsidiaries and KDSM, LLC
Condensed Financial Statements, Captions [Line Items]
Revenue									2,841	2,856	2,507
Media programming and production expenses									1,238	1,131	1,013
Selling, general and administrative									663	613	522
Depreciation, amortization and other operating expenses									278	258	132
Total operating expenses									2,179	2,002	1,667
Operating Income (Loss)									662	854	840
Equity in earnings of consolidated subsidiaries									0	0	0
Interest expense									(4)	(4)	(4)
Other income (expense)									(53)	(58)	(6)
Total other expense, net									(57)	(62)	(10)
Income tax benefit (provision)									(21)	(62)	(30)
NET INCOME									584	730	800
Net income attributable to the redeemable noncontrolling interests									0
Net income attributable to the noncontrolling interests									0	0	0
Net income (loss) attributable to Sinclair Broadcast Group									584	730	800
Comprehensive income (loss)									584	730	800
Reportable legal entities | Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue									1,487	293	210
Media programming and production expenses									894	141	124
Selling, general and administrative									202	20	15
Depreciation, amortization and other operating expenses									334	207	51
Total operating expenses									1,430	368	190
Operating Income (Loss)									57	(75)	20
Equity in earnings of consolidated subsidiaries									0	0	0
Interest expense									(216)	(18)	(22)
Other income (expense)									24	0	(7)
Total other expense, net									(192)	(18)	(29)
Income tax benefit (provision)									19	6	0
NET INCOME									(116)	(87)	(9)
Net income attributable to the redeemable noncontrolling interests									(48)
Net income attributable to the noncontrolling interests									(10)	(5)	(18)
Net income (loss) attributable to Sinclair Broadcast Group									(174)	(92)	(27)
Comprehensive income (loss)									(116)	(87)	(9)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenue									(123)	(94)	(81)
Media programming and production expenses									(59)	(81)	(73)
Selling, general and administrative									(40)	(2)	(2)
Depreciation, amortization and other operating expenses									(14)	(7)	(2)
Total operating expenses									(113)	(90)	(77)
Operating Income (Loss)									(10)	(4)	(4)
Equity in earnings of consolidated subsidiaries									(742)	(1,072)	(1,373)
Interest expense									19	15	19
Other income (expense)									(5)	0	0
Total other expense, net									(728)	(1,057)	(1,354)
Income tax benefit (provision)									0	0	0
NET INCOME									(738)	(1,061)	(1,358)
Net income attributable to the redeemable noncontrolling interests									0
Net income attributable to the noncontrolling interests									0	0	0
Net income (loss) attributable to Sinclair Broadcast Group									(738)	(1,061)	(1,358)
Comprehensive income (loss)									$ (738)	$ (1,065)	$ (1,375)