Loans and Allowance for Loan Losses - Summary of Maturities of Loan Portfolio (Details) (Commercial Financial, Agricultural And Construction [Member], USD $)	Sep. 30, 2014
Commercial Financial, Agricultural And Construction [Member]
In one year or less	$ 9,676,206
After one year but within five years	44,569,369
After five years	2,939,138
Total	$ 57,184,713

Distribution of loans which are due after one year but within five years..

No definition available.

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Namespace Prefix:	SGB_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant