Condensed Consolidating Financial Information Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017		Dec. 31, 2017		Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			$ 306,849	$ 171,494
Capital expenditures	$ (22,505)	$ (13,324)	(47,452)	(41,423)
Spectrum repack reimbursements			6,967	0
Net proceeds from the sale of business			0	554,487
Proceeds from FCC spectrum auction			0	172,102		$ 172,000
Proceeds from sales of real estate and other assets			66	61,240
Proceeds from the sales of investments			15,232	148,321
Distribution from equity investment			0	4,608
Other, net			1,529	780
Net cash (used in) provided by investing activities			(23,658)	900,115
Long-term borrowings			0	202,694
Repayments of long-term debt			0	(703,527)
Long-term debt issuance costs			0	(1,689)
Payments of dividends			(65,776)	(564,499)
Tax withholdings related to net share settlements of share-based awards			(5,765)	(8,030)
Proceeds from stock option exercises			982	11,231
Contributions from noncontrolling interests, net			475	1,318
Change in intercompany receivables and payables and intercompany contributions (1)			0	0	[1]
Net cash used in financing activities			(70,084)	(1,062,502)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash			213,107	9,107
Cash, cash equivalents and restricted cash, beginning of period (1)			691,251	611,198	[2]	611,198	[2]
Cash, cash equivalents and restricted cash, end of period	904,358	620,305	904,358	620,305		691,251
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents	887,751	602,739	887,751	602,739		673,685
Restricted cash and cash equivalents	16,607	17,566	16,607	17,566		17,566		$ 17,566
Cash, cash equivalents and restricted cash, end of period	904,358	620,305	904,358	620,305		691,251
Non-cash settlement of intercompany balances				54,000
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			0	0
Capital expenditures			0	0
Spectrum repack reimbursements			0
Net proceeds from the sale of business				0
Proceeds from FCC spectrum auction				0
Proceeds from sales of real estate and other assets			0	0
Proceeds from the sales of investments			0	0
Distribution from equity investment				0
Other, net			0	0
Net cash (used in) provided by investing activities			0	0
Long-term borrowings				0
Repayments of long-term debt				0
Long-term debt issuance costs				0
Payments of dividends			0	0
Tax withholdings related to net share settlements of share-based awards			0	0
Proceeds from stock option exercises			0	0
Contributions from noncontrolling interests, net			0	0
Change in intercompany receivables and payables and intercompany contributions (1)			0	0	[1]
Net cash used in financing activities			0	0
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash			0	0
Cash, cash equivalents and restricted cash, beginning of period (1)			0	0		0
Cash, cash equivalents and restricted cash, end of period	0	0	0	0		0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents	0	0	0	0		0
Restricted cash and cash equivalents	0	0	0	0		0
Cash, cash equivalents and restricted cash, end of period	0	0	0	0		0
Parent (Tribune Media Company) | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			(145,783)	(184,784)
Capital expenditures			(8,822)	(3,812)
Spectrum repack reimbursements			0
Net proceeds from the sale of business				574,817
Proceeds from FCC spectrum auction				0
Proceeds from sales of real estate and other assets			0	0
Proceeds from the sales of investments			0	5,769
Distribution from equity investment				0
Other, net			0	0
Net cash (used in) provided by investing activities			(8,822)	576,774
Long-term borrowings				202,694
Repayments of long-term debt				(688,708)
Long-term debt issuance costs				(1,689)
Payments of dividends			(65,776)	(564,499)
Tax withholdings related to net share settlements of share-based awards			(5,765)	(8,030)
Proceeds from stock option exercises			982	11,231
Contributions from noncontrolling interests, net			0	0
Change in intercompany receivables and payables and intercompany contributions (1)			435,104	680,631	[1]
Net cash used in financing activities			364,545	(368,370)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash			209,940	23,620
Cash, cash equivalents and restricted cash, beginning of period (1)			687,868	592,204		592,204
Cash, cash equivalents and restricted cash, end of period	897,808	615,824	897,808	615,824		687,868
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents	881,201	598,258	881,201	598,258		670,302
Restricted cash and cash equivalents	16,607	17,566	16,607	17,566		17,566
Cash, cash equivalents and restricted cash, end of period	897,808	615,824	897,808	615,824		687,868
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			469,683	346,753
Capital expenditures			(36,175)	(33,645)
Spectrum repack reimbursements			6,967
Net proceeds from the sale of business				(8,168)
Proceeds from FCC spectrum auction				172,102
Proceeds from sales of real estate and other assets			66	61,240
Proceeds from the sales of investments			15,232	142,552
Distribution from equity investment				4,608
Other, net			(84)	(25)
Net cash (used in) provided by investing activities			(13,994)	338,664
Long-term borrowings				0
Repayments of long-term debt				0
Long-term debt issuance costs				0
Payments of dividends			0	0
Tax withholdings related to net share settlements of share-based awards			0	0
Proceeds from stock option exercises			0	0
Contributions from noncontrolling interests, net			0	0
Change in intercompany receivables and payables and intercompany contributions (1)			(453,796)	(690,989)	[1]
Net cash used in financing activities			(453,796)	(690,989)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash			1,893	(5,572)
Cash, cash equivalents and restricted cash, beginning of period (1)			1,501	7,378		7,378
Cash, cash equivalents and restricted cash, end of period	3,394	1,806	3,394	1,806		1,501
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents	3,394	1,806	3,394	1,806		1,501
Restricted cash and cash equivalents	0	0	0	0		0
Cash, cash equivalents and restricted cash, end of period	3,394	1,806	3,394	1,806		1,501
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			(17,051)	9,525
Capital expenditures			(2,455)	(3,966)
Spectrum repack reimbursements			0
Net proceeds from the sale of business				(12,162)
Proceeds from FCC spectrum auction				0
Proceeds from sales of real estate and other assets			0	0
Proceeds from the sales of investments			0	0
Distribution from equity investment				0
Other, net			1,613	805
Net cash (used in) provided by investing activities			(842)	(15,323)
Long-term borrowings				0
Repayments of long-term debt				(14,819)
Long-term debt issuance costs				0
Payments of dividends			0	0
Tax withholdings related to net share settlements of share-based awards			0	0
Proceeds from stock option exercises			0	0
Contributions from noncontrolling interests, net			475	1,318
Change in intercompany receivables and payables and intercompany contributions (1)			18,692	10,358	[1]
Net cash used in financing activities			19,167	(3,143)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash			1,274	(8,941)
Cash, cash equivalents and restricted cash, beginning of period (1)			1,882	11,616		11,616
Cash, cash equivalents and restricted cash, end of period	3,156	2,675	3,156	2,675		1,882
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents	3,156	2,675	3,156	2,675		1,882
Restricted cash and cash equivalents	0	0	0	0		0
Cash, cash equivalents and restricted cash, end of period	$ 3,156	$ 2,675	$ 3,156	$ 2,675		$ 1,882

[1] (1)Excludes the impact of a $54 million non-cash settlement of intercompany balances upon dissolution of certain Guarantor and Non-Guarantor subsidiaries included in the Gracenote Sale.

[2] (1)Cash, cash equivalents and restricted cash at the beginning of the nine months ended September 30, 2017 of $611 million are comprised of $595 million of cash, cash equivalents and restricted cash from continuing operations as reflected in the Company’s unaudited Condensed Consolidated Balance Sheets and $16 million of cash, cash equivalents and restricted cash reflected in total assets of discontinued operations.