ACQUISITIONS (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended					0 Months Ended	3 Months Ended		9 Months Ended			1 Months Ended		1 Months Ended		1 Months Ended		1 Months Ended	0 Months Ended	3 Months Ended			9 Months Ended			1 Months Ended		1 Months Ended		1 Months Ended		1 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended						9 Months Ended	12 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended	0 Months Ended		2 Months Ended	3 Months Ended	9 Months Ended		0 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 01, 2012 WLYH in Harrisburg, PA	Sep. 30, 2012 WLWC-TV	Sep. 30, 2013 WLWC-TV	Sep. 30, 2012 WLWC-TV	Dec. 01, 2012 WSTR and KMYS Deerfield item	Sep. 30, 2012 WLAJ-TV	Sep. 30, 2013 WLAJ-TV	Sep. 30, 2012 WLAJ-TV	Sep. 30, 2013 6.125% Notes	Jun. 28, 2013 6.125% Notes	Oct. 31, 2012 6.125% Notes	Jan. 02, 2012 Four Points item	Sep. 30, 2013 Four Points	Sep. 30, 2012 Four Points	Sep. 30, 2013 Four Points	Sep. 30, 2012 Four Points	Dec. 31, 2011 Four Points	Jan. 31, 2012 Four Points Network affiliations	Jan. 02, 2012 Four Points Network affiliations	Jan. 31, 2012 Four Points Decaying advertiser base	Jan. 02, 2012 Four Points Decaying advertiser base	Jan. 31, 2012 Four Points Other intangible assets	Jan. 02, 2012 Four Points Other intangible assets	Jan. 31, 2012 Four Points Term Loan B	Apr. 02, 2012 Freedom item	Sep. 30, 2013 Freedom	Sep. 30, 2012 Freedom	Mar. 31, 2012 Freedom	Sep. 30, 2013 Freedom	Sep. 30, 2012 Freedom	Dec. 31, 2011 Freedom	Apr. 30, 2012 Freedom Network affiliations	Apr. 02, 2012 Freedom Network affiliations	Apr. 30, 2012 Freedom Decaying advertiser base	Apr. 02, 2012 Freedom Decaying advertiser base	Apr. 30, 2012 Freedom Other intangible assets	Apr. 02, 2012 Freedom Other intangible assets	Apr. 30, 2012 Freedom Term Loan A	Apr. 30, 2012 Freedom Term Loan B	Dec. 01, 2012 Newport item	Sep. 30, 2013 Newport	Sep. 30, 2013 Newport	Dec. 01, 2012 Newport Network affiliations	Dec. 01, 2012 Newport Decaying advertiser base	Dec. 01, 2012 Newport Other intangible assets	Dec. 01, 2012 Newport 6.125% Notes	Dec. 01, 2012 WPMI and WJTC Deerfield	Feb. 01, 2013 WHAM Deerfield	Sep. 30, 2013 Other acquisitions item	Dec. 31, 2012 Other acquisitions item	Sep. 30, 2013 WTTA-TV	Sep. 30, 2013 WTTA-TV	Dec. 31, 2012 WTTA-TV	May 31, 2013 CMG item	Aug. 08, 2013 Fisher Communications item	Sep. 30, 2013 Fisher Communications	Sep. 30, 2013 Fisher Communications	Sep. 30, 2013 Fisher Communications	Sep. 30, 2013 Fisher Communications KIDK and KXPI item	Aug. 08, 2013 Fisher Communications Network affiliations	Aug. 08, 2013 Fisher Communications Decaying advertiser base	Aug. 08, 2013 Fisher Communications Other intangible assets	Sep. 30, 2013 TTBG LLC item	Oct. 02, 2013 TTBG LLC item
Acquisitions
Number of television stations																7													8															7									8	5					22				2				2	2
Number of markets																4													7															6									6	3				4	8								1
Number of radio stations in Seattle market																																																											4
Cash paid for acquisition (in dollar per share)																																																											$ 41.0
Cash paid																$ 200,000,000													$ 385,000,000															$ 460,500,000									$ 136,900,000	$ 45,100,000					$ 373,200,000
Working capital adjustment																(900,000)													300,000															(1,300,000)									(4,400,000)	(700,000)
Non-controlling interests related to, and amounts paid by certain VIE's for, the license assets																																																					3,100,000	4,400,000
Amount of draw under incremental loan commitment used to finance acquisition																												180,000,000														157,500,000	192,500,000
Escrow deposit used to fund acquisition																20,000,000													38,500,000															41,300,000
Interest rate (as a percent)													6.125%	6.125%	6.125%																																			6.125%
Number of stations whose license assets were sold									2
Price of assets acquired/sold					200,000				10,700,000																																										6,000,000	6,000,000											5,900,000
Estimated projected benefit obligation																																																											23,500,000
Estimated discount rate (as a percent)																																																											3.60%
Estimated fair value of annuity contracts and cash surrender value of the life insurance policies																																																											17,900,000
Allocated fair value of acquired assets and assumed liabilities
Cash																																																											13,531,000
Accounts Receivable																																																											29,962,000
Prepaid expenses and other current assets																456,000													373,000															1,390,000									1,991,000	160,000					2,079,000
Program contract costs																3,731,000													3,520,000															10,378,000									7,594,000	1,638,000					10,954,000
Property and equipment																34,578,000													54,109,000															53,883,000									35,439,000	16,545,000					48,616,000
Broadcast licenses																10,658,000													10,424,000															15,581,000									1,611,000	2,679,000					11,058,000
Definite-lived intangible assets																93,800,000							66,900,000		9,800,000		17,100,000		140,963,000								93,100,000		25,100,000		22,800,000			240,013,000			176,000,000	23,700,000	40,300,000				48,049,000	22,546,000					156,332,000					100,600,000	15,000,000	40,800,000
Other assets																548,000													278,000															1,097,000															24,632,000
Assets Held for Sale																																																											5,900,000
Accrued liabilities																(381,000)													(589,000)															(3,928,000)									(2,086,000)	(1,178,000)
Accounts payable and accrued liabilities																																																											(20,342,000)
Program contracts payable																(5,157,000)													(3,404,000)															(11,634,000)									(7,625,000)	(4,252,000)					(10,954,000)
Deferred Tax Liability																																																											(50,416,000)
Other long-term liabilities																																																											(25,482,000)
Fair value of identifiable net assets acquired																138,233,000													205,674,000															306,780,000									84,973,000	38,138,000					195,870,000
Goodwill																60,843,000													179,609,000															164,621,000									50,674,000	10,661,000					177,326,000
Total																199,076,000													385,283,000															471,401,000									135,647,000	48,799,000					373,196,000
Goodwill deductible for tax purposes																																																											19,500,000
Amortization period																						15 years		10 years												15 years		10 years									15 years	10 years																15 years	10 years
Weighted average life																										14 years														16 years									14 years																	15 years
Amount paid for funding working capital needs																					8,100,000											9,600,000			1,500,000
Net broadcast revenues	303,028,000	225,023,000	835,223,000	633,493,000													17,900,000	18,700,000	54,300,000	52,900,000										26,200,000	26,800,000	10,000,000	79,900,000	52,500,000											36,100,000	109,300,000									29,500,000	47,000,000					25,900,000	25,900,000
Operating income (loss)	72,848,000	78,398,000	220,784,000	210,181,000													4,400,000	4,100,000	14,000,000	11,600,000										6,700,000	5,000,000		20,800,000	14,000,000											5,500,000	25,300,000									6,700,000	10,500,000					8,200,000	8,200,000
Severance expense related to executives and employees																																																												4,300,000
Net broadcast revenues						1,400,000	1,400,000	4,100,000		1,100,000	700,000	2,100,000
Operating income (loss)						(200,000)	200,000	100,000		(200,000)	100,000	0
Transaction costs	3,500,000		3,500,000
Revenue from discontinued operations excluded from pro forma revenues											1,000,000
Costs incurred in corporate, general and administrative expenses	100,000	400,000	1,000,000	900,000
Difference between the purchase price and the historical cost basis recorded as a reduction in additional paid-in capital																																																									23,600,000
Difference between the purchase price and the historical cost basis recorded as a reduction in additional paid-in capital, tax amount																																																									15,600,000
Pro Forma Information
Total revenues	354,545,000	335,849,000	1,030,175,000	972,305,000
Net Income	28,380,000	29,877,000	57,487,000	84,146,000
Net Income attributable to Sinclair Broadcast Group	$ 28,071,000	$ 29,733,000	$ 57,072,000	$ 84,139,000
Basic and diluted earnings per share attributable to Sinclair Broadcast Group (in dollars per share)	$ 0.28	$ 0.37	$ 0.70	$ 1.04