Ticking fee rate for funds borrowed, under the debt agreement.

No definition available.

Name:	gtn_DebtInstrumentTickingFeeRate
Namespace Prefix:	gtn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Ticking fee rate, plus LIBOR, for funds borrowed, under the debt agreement.

+ References

No definition available.

+ Details

Name:	gtn_DebtInstrumentTickingFeeRatePlusLIBOR
Namespace Prefix:	gtn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=gtn_Notes2027Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=gtn_The2017SeniorCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=gtn_The2018SeniorCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 11 - Subsequent Events (Details Textual) - USD ($) $ in Thousands		3 Months Ended
	Jan. 16, 2019	Dec. 31, 2018	Sep. 30, 2018
2027 Notes [Member] \| Scenario, Forecast [Member]
Debt Instrument, Interest Rate, Stated Percentage		7.00%
Revolving Credit Facility [Member] \| The 2017 Senior Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity			$ 100,000
Revolving Credit Facility [Member] \| The 2018 Senior Credit Facility [Member] \| Scenario, Forecast [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 200,000
Debt Instrument, Term		5 years
Debt Instrument, Ticking Fee Rate		1.25%
Debt Instrument, Ticking Fee Rate, Plus LIBOR	2.50%