Condensed Consolidating Financial Information Statement of Cash Flows (Details) - USD ($) $ in Thousands		3 Months Ended			12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017		Dec. 31, 2017		Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities		$ 157,395	$ 75,296
Capital expenditures		(13,673)	(14,634)
Investments		(28)	0
Net proceeds from the sale of business		0	551,419
Sale of partial interest of equity method investment		833	0
Proceeds from sales of real estate and other assets		44	44,315
Proceeds from the sale of investments		3,057	4,950
Net cash (used in) provided by investing activities		(9,767)	586,050
Long-term borrowings		0	202,694
Repayments of long-term debt		0	(584,245)
Long-term debt issuance costs		0	(1,689)
Payments of dividends		(21,922)	(520,849)
Tax withholdings related to net share settlements of share-based awards		(5,493)	(7,053)
Proceeds from stock option exercises		581	2,385
Change in intercompany receivables and payables and intercompany contributions (1)		0	0	[1]
Net cash used in financing activities		(26,834)	(908,757)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash		120,794	(247,411)
Cash, cash equivalents and restricted cash, beginning of period (1)	[2]	691,251	611,198		$ 611,198
Cash, cash equivalents and restricted cash, end of period		812,045	363,787		691,251	[2]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents		795,438	346,221		673,685
Restricted cash and cash equivalents		16,607	17,566		17,566		$ 17,566
Cash, cash equivalents and restricted cash, end of period		812,045	363,787		691,251	[2]
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
Investments		0
Net proceeds from the sale of business			0
Sale of partial interest of equity method investment		0
Proceeds from sales of real estate and other assets		0	0
Proceeds from the sale of investments		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
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
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents		0	0		0
Restricted cash and cash equivalents		0	0		0
Cash, cash equivalents and restricted cash, end of period		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		(43,982)	(133,188)
Capital expenditures		(2,813)	(1,413)
Investments		0
Net proceeds from the sale of business			571,749
Sale of partial interest of equity method investment		0
Proceeds from sales of real estate and other assets		0	0
Proceeds from the sale of investments		0	4,950
Net cash (used in) provided by investing activities		(2,813)	575,286
Long-term borrowings			202,694
Repayments of long-term debt			(583,232)
Long-term debt issuance costs			(1,689)
Payments of dividends		(21,922)	(520,849)
Tax withholdings related to net share settlements of share-based awards		(5,493)	(7,053)
Proceeds from stock option exercises		581	2,385
Change in intercompany receivables and payables and intercompany contributions (1)		193,972	233,965	[1]
Net cash used in financing activities		167,138	(673,779)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash		120,343	(231,681)
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		808,211	360,523		687,868
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents		791,604	342,957		670,302
Restricted cash and cash equivalents		16,607	17,566		17,566
Cash, cash equivalents and restricted cash, end of period		808,211	360,523		687,868
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities		227,838	209,514
Capital expenditures		(10,836)	(12,468)
Investments		(28)
Net proceeds from the sale of business			(8,168)
Sale of partial interest of equity method investment		833
Proceeds from sales of real estate and other assets		44	44,315
Proceeds from the sale of investments		3,057	0
Net cash (used in) provided by investing activities		(6,930)	23,679
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
Change in intercompany receivables and payables and intercompany contributions (1)		(221,276)	(239,190)	[1]
Net cash used in financing activities		(221,276)	(239,190)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash		(368)	(5,997)
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		1,133	1,381		1,501
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents		1,133	1,381		1,501
Restricted cash and cash equivalents		0	0		0
Cash, cash equivalents and restricted cash, end of period		1,133	1,381		1,501
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities		(26,461)	(1,030)
Capital expenditures		(24)	(753)
Investments		0
Net proceeds from the sale of business			(12,162)
Sale of partial interest of equity method investment		0
Proceeds from sales of real estate and other assets		0	0
Proceeds from the sale of investments		0	0
Net cash (used in) provided by investing activities		(24)	(12,915)
Long-term borrowings			0
Repayments of long-term debt			(1,013)
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
Change in intercompany receivables and payables and intercompany contributions (1)		27,304	5,225	[1]
Net cash used in financing activities		27,304	4,212
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash		819	(9,733)
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		2,701	1,883		1,882
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations [Abstract]
Cash and cash equivalents		2,701	1,883		1,882
Restricted cash and cash equivalents		0	0		0
Cash, cash equivalents and restricted cash, end of period		$ 2,701	$ 1,883		$ 1,882

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

[2] (1)Cash, cash equivalents and restricted cash at the beginning of the three months ended March 31, 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 current assets of discontinued operations.