Loans and Allowance for Loan Losses - Summary of Maturities of Loan Portfolio (Details) (Commercial Financial, Agricultural And Construction [Member], USD $)	Mar. 31, 2014
Commercial Financial, Agricultural And Construction [Member]
In one year or less	$ 20,783,902
After one year but within five years	36,363,475
After five years	2,930,872
Total	$ 60,078,249

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