Name:	gtn_EmployeeBenefitPlanReconciliationToForm5500ChangeInNetAssetAvailableForBenefitDecreaseForCurrentYearEmployerContributionsReceivable
Namespace Prefix:	gtn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Employee benefit plan reconciliation to form 5500 change in net asset available for benefit increase for current year employer contributions receivable.

No definition available.

Name:	gtn_EmployeeBenefitPlanReconciliationToForm5500ChangeInNetAssetAvailableForBenefitIncreaseForCurrentYearEmployerContributionsReceivable
Namespace Prefix:	gtn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Employee benefit plan reconciliation to form 5500 change in net asset available for benefit increase for pending settlement.

No definition available.

Name:	gtn_EmployeeBenefitPlanReconciliationToForm5500ChangeInNetAssetAvailableForBenefitIncreaseForPendingSettlement
Namespace Prefix:	gtn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of increase (decrease) in net asset available for benefit to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule III))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 45
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477509/962-325-45-8

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of increase (decrease) in net asset available for benefit from net income (loss) as reported in Form 5500 caption for employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Form 5500 is form provided by Department of the Treasury, Internal Revenue Service (IRS); Department of Labor (DOL), Employee Benefit Security Administration (EBSA); and Pension Benefit Guaranty Corporation (PBGC).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 1
-Paragraph b
-Subparagraph (3)
-Publisher DOL-EBSA

Name:	us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionNetIncomeLoss
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of decrease in net asset available for benefit from deemed distribution in current period to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) to reconcile change in net asset available for benefit per financial statement to Form 5500 caption. Form 5500 is form provided by Department of the Treasury, Internal Revenue Service (IRS); Department of Labor (DOL), Employee Benefit Security Administration (EBSA); and Pension Benefit Guaranty Corporation (PBGC).

Name:	us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500ChangeInNetAssetAvailableForBenefitDecreaseForDeemedDistributionCurrentPeriod
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of increase in net asset available for benefit from deemed distribution in prior period to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) to reconcile change in net asset available for benefit per financial statement to Form 5500 caption. Form 5500 is form provided by Department of the Treasury, Internal Revenue Service (IRS); Department of Labor (DOL), Employee Benefit Security Administration (EBSA); and Pension Benefit Guaranty Corporation (PBGC).

Name:	us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500ChangeInNetAssetAvailableForBenefitIncreaseForDeemedDistributionPriorPeriod
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.