Average annual compensation

No definition available.

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- Definition

Ceo Employment Agreement

+ References

No definition available.

+ Details

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Namespace Prefix:	sga_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt of related party guaranteed by the Company.

+ References

No definition available.

+ Details

Name:	sga_DebtGuaranteedRelatedParty
Namespace Prefix:	sga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Deferred Compensation Details

+ References

No definition available.

+ Details

Name:	sga_DeferredCompensationDetails
Namespace Prefix:	sga_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Extension fees paid during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	sga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Option to purchase assets of Station KFJX.

+ References

No definition available.

+ Details

Name:	sga_OptionAgreementForKfjx
Namespace Prefix:	sga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fees paid under various station agreements.

+ References

No definition available.

+ Details

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Namespace Prefix:	sga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Time Brokerage Agreement fees paid.

+ References

No definition available.

+ Details

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Namespace Prefix:	sga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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

- Definition

Amount of fee and commission revenue classified as other.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

This element represents the payments that the lessee is obligated to make or can be required to make in connection with a property under the terms of an agreement classified as an operating lease, excluding contingent rentals and a guarantee by the lessee of the lessor's debt and the lessee's obligation to pay (apart from the rental payments) executory costs such as insurance, maintenance, and taxes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77910348&loc=d3e34039-112682

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

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Balance Type:	debit
Period Type:	duration

- Definition

Cash received for rents during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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Related Party Transactions (Details Textual) - USD ($)	8 Months Ended	12 Months Ended
Related Party Transactions (Details Textual) - USD ($)	Aug. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 09, 2017	Mar. 31, 2003
Related Party Transaction [Line Items]
CEO Employment Agreement		In June2011, we entered into a new employment agreement with Edward K. Christian, Chairman, President and CEO, which became effective as of June1, 2011, and replaces and supersedes his prior employment agreement. On February 12, 2016 we entered into an amendment to the agreement. The amendment extends the term of the employment agreement to March 31, 2021. The amendment also states that on each anniversary of the effective date of the employment agreement, the Companys Compensation committee shall determine in its discretion the amount of any annual increases (which shall not be less than the greater of 4 % or a defined cost of living increase). Mr.Christian may defer any or all of his annual salary.
Deferred Compensation Details		On December 21, 2015, Mr. Christian agreed to defer approximately $100,000 of his 2016 salary which was paid 100% on January 6, 2017. On December 13, 2016, Mr. Christian agreed to defer approximately $100,000 of his 2017 salary to be paid 100% on January 5, 2018. On December 5, 2017, Mr. Christian agreed to defer approximately $100,000 of his 2018 salary to be paid 100% on January 4, 2019.
Option Agreement For Kfjx		$ 1,200,000
Equity Method Investment, Ownership Percentage		100.00%
Disposal Group, Including Discontinued Operation, Consideration					$ 23,000,000
Operating Leases, Rent Expense, Minimum Rentals		$ 3,300
CEO [Member]
Related Party Transaction [Line Items]
Average Annual Compensation		1,759,000
Surtsey Productions Inc [Member]
Related Party Transaction [Line Items]
Proceeds from Rents Received	$ 3,000		$ 6,000	$ 6,000
Surtsey Media [Member]
Related Party Transaction [Line Items]
Tba Fees Kvct		3,800	3,900	3,800
Extension Fee Paid		27,950
Debt Guaranteed Related Party						$ 1,250,000
Station Agreement Fees Kfjx		5,200	$ 5,100	$ 5,000
Extension fees paid, KFJX		$ 37,050