CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
NET CASH FLOWS (USED IN) FROM OPERATING ACTIVITIES	$ 69,642	$ 134,015
CASH FLOWS (USED IN) FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	(20,774)	(25,851)
Acquisition of businesses, net of cash acquired	(8,000)	(384,659)
Purchase of alarm monitoring contracts	(5,682)	(7,017)
Proceeds from sale of assets	192,149
Investments in equity and cost method investees	(3,080)	(19,874)
Loans to affiliates	0	(19,500)
Other, net	546	2,265
Net cash flows from (used in) investing activities	155,159	(454,636)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable and commercial bank financing	163,089	598,850
Repayments of notes payable, commercial bank financing and capital leases	(284,422)	(261,230)
Proceeds from the sale of Class A Common Stock	487,883	0
Dividends paid on Class A and Class B Common Stock	(16,257)	(15,675)
Distributions to noncontrolling interests	(15,708)	(2,513)
Increase (decrease) in intercompany payables	0	0
Other, net	(3,670)	(9,772)
Net cash flows from financing activities	330,915	312,173
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	555,716	(8,448)
CASH AND CASH EQUIVALENTS, beginning of period	259,984	149,972
CASH AND CASH EQUIVALENTS, end of period	815,700	141,524
Reportable legal entities | Sinclair Broadcast Group, Inc.
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
NET CASH FLOWS (USED IN) FROM OPERATING ACTIVITIES	1,126	823
CASH FLOWS (USED IN) FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	(50)	0
Acquisition of businesses, net of cash acquired	0	0
Purchase of alarm monitoring contracts	0	0
Proceeds from sale of assets	0
Investments in equity and cost method investees	(945)	0
Loans to affiliates		0
Other, net	2,266	1,197
Net cash flows from (used in) investing activities	1,271	1,197
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable and commercial bank financing	0	0
Repayments of notes payable, commercial bank financing and capital leases	0	0
Proceeds from the sale of Class A Common Stock	487,883
Dividends paid on Class A and Class B Common Stock	(16,257)	(15,675)
Distributions to noncontrolling interests	0
Increase (decrease) in intercompany payables	(471,945)	15,368
Other, net	(2,078)	(1,713)
Net cash flows from financing activities	(2,397)	(2,020)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	0	0
CASH AND CASH EQUIVALENTS, beginning of period	0	0
CASH AND CASH EQUIVALENTS, end of period	0	0
Reportable legal entities | Sinclair Television Group, Inc.
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
NET CASH FLOWS (USED IN) FROM OPERATING ACTIVITIES	(44,685)	(20,655)
CASH FLOWS (USED IN) FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	(3,259)	(1,479)
Acquisition of businesses, net of cash acquired	0	0
Purchase of alarm monitoring contracts	0	0
Proceeds from sale of assets	0
Investments in equity and cost method investees	(300)	(10,000)
Loans to affiliates		(19,500)
Other, net	(3,083)	0
Net cash flows from (used in) investing activities	(6,642)	(30,979)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable and commercial bank financing	159,669	595,000
Repayments of notes payable, commercial bank financing and capital leases	(172,519)	(257,682)
Proceeds from the sale of Class A Common Stock	0
Dividends paid on Class A and Class B Common Stock	0	0
Distributions to noncontrolling interests	0
Increase (decrease) in intercompany payables	615,437	(290,337)
Other, net	(360)	(5,800)
Net cash flows from financing activities	602,227	41,181
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	550,900	(10,453)
CASH AND CASH EQUIVALENTS, beginning of period	232,297	115,771
CASH AND CASH EQUIVALENTS, end of period	783,197	105,318
Reportable legal entities | Guarantor Subsidiaries and KDSM, LLC
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
NET CASH FLOWS (USED IN) FROM OPERATING ACTIVITIES	127,520	145,404
CASH FLOWS (USED IN) FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	(16,840)	(23,239)
Acquisition of businesses, net of cash acquired	(8,000)	(374,284)
Purchase of alarm monitoring contracts	0	0
Proceeds from sale of assets	0
Investments in equity and cost method investees	(47)	(47)
Loans to affiliates		0
Other, net	357	(210)
Net cash flows from (used in) investing activities	(24,530)	(397,780)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable and commercial bank financing	0	0
Repayments of notes payable, commercial bank financing and capital leases	(445)	(461)
Proceeds from the sale of Class A Common Stock	0
Dividends paid on Class A and Class B Common Stock	0	0
Distributions to noncontrolling interests	0
Increase (decrease) in intercompany payables	(102,763)	262,392
Other, net	586	263
Net cash flows from financing activities	(102,622)	262,194
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	368	9,818
CASH AND CASH EQUIVALENTS, beginning of period	10,675	235
CASH AND CASH EQUIVALENTS, end of period	11,043	10,053
Reportable legal entities | Non- Guarantor Subsidiaries
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
NET CASH FLOWS (USED IN) FROM OPERATING ACTIVITIES	(13,853)	779
CASH FLOWS (USED IN) FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	(806)	(1,323)
Acquisition of businesses, net of cash acquired	0	(10,375)
Purchase of alarm monitoring contracts	(5,682)	(7,017)
Proceeds from sale of assets	192,149
Investments in equity and cost method investees	(1,788)	(9,827)
Loans to affiliates		0
Other, net	1,006	1,278
Net cash flows from (used in) investing activities	184,879	(27,264)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable and commercial bank financing	3,420	3,850
Repayments of notes payable, commercial bank financing and capital leases	(111,458)	(3,087)
Proceeds from the sale of Class A Common Stock	0
Dividends paid on Class A and Class B Common Stock	0	0
Distributions to noncontrolling interests	(15,708)
Increase (decrease) in intercompany payables	(40,939)	20,489
Other, net	(1,893)	(2,580)
Net cash flows from financing activities	(166,578)	18,672
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	4,448	(7,813)
CASH AND CASH EQUIVALENTS, beginning of period	17,012	33,966
CASH AND CASH EQUIVALENTS, end of period	21,460	26,153
Eliminations
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
NET CASH FLOWS (USED IN) FROM OPERATING ACTIVITIES	(466)	7,664
CASH FLOWS (USED IN) FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	181	190
Acquisition of businesses, net of cash acquired	0	0
Purchase of alarm monitoring contracts	0	0
Proceeds from sale of assets	0
Investments in equity and cost method investees	0	0
Loans to affiliates		0
Other, net	0	0
Net cash flows from (used in) investing activities	181	190
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Proceeds from notes payable and commercial bank financing	0	0
Repayments of notes payable, commercial bank financing and capital leases	0	0
Proceeds from the sale of Class A Common Stock	0
Dividends paid on Class A and Class B Common Stock	0	0
Distributions to noncontrolling interests	0
Increase (decrease) in intercompany payables	210	(7,912)
Other, net	75	58
Net cash flows from financing activities	285	(7,854)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	0	0
CASH AND CASH EQUIVALENTS, beginning of period	0	0
CASH AND CASH EQUIVALENTS, end of period	$ 0	$ 0