Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Investment securities held to maturity	$ 62,841,404	$ 60,019,146
Allowance for loan losses	3,114,151SGB_LoansLossesForReceivableAllowance	3,077,561SGB_LoansLossesForReceivableAllowance
Certificates of deposit	100,000us-gaap_DepositsWholesale	100,000us-gaap_DepositsWholesale
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	5,000,000us-gaap_CommonStockSharesAuthorized	5,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	4,293,835us-gaap_CommonStockSharesIssued	4,293,835us-gaap_CommonStockSharesIssued
Treasury stock, at cost	$ 1,745,998us-gaap_TreasuryStockCarryingBasis	$ 1,745,998us-gaap_TreasuryStockCarryingBasis

Loans losses for receivable allowance.

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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The aggregate amount of all wholesale deposit accounts including certificates of deposits.

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Fair value of investments in debt securities classified as held-to-maturity.

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Cost basis for treasury stock acquired for purposes other than retirement.

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