Deposits (Amounts and scheduled maturities of all certificates of deposit) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Banking and Thrift [Abstract]
Time deposits, $250,000 or more	$ 69,600,000sfdl_Timedeposits250000ormore	$ 53,100,000sfdl_Timedeposits250000ormore
Time Deposits, Fiscal Year Maturity [Abstract]
Within 1 Year	142,490,027us-gaap_TimeDepositMaturitiesYearOne	163,680,585us-gaap_TimeDepositMaturitiesYearOne
After 1 Year, Within 2 Years	57,481,254us-gaap_TimeDepositMaturitiesYearTwo	45,089,513us-gaap_TimeDepositMaturitiesYearTwo
After 2 Years, Within 3 Years	22,273,310us-gaap_TimeDepositMaturitiesYearThree	22,483,793us-gaap_TimeDepositMaturitiesYearThree
After 3 Years, Within 4 Years	18,114,738us-gaap_TimeDepositMaturitiesYearFour	8,996,498us-gaap_TimeDepositMaturitiesYearFour
After 4 Years, Within 5 Years	12,891,700us-gaap_TimeDepositMaturitiesYearFive	16,633,151us-gaap_TimeDepositMaturitiesYearFive
Thereafter	0	0
Time Deposits	$ 253,251,029us-gaap_TimeDeposits	$ 256,883,540us-gaap_TimeDeposits

Time deposits, $250,000 or more

No definition available.

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- Definition

Amount of time deposits maturing after the fifth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

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Amount of time deposits maturing in the fifth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

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- Definition

Amount of time deposits maturing in the fourth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

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Amount of time deposits maturing in the next fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

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- Definition

Amount of time deposits maturing in the third fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

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- Definition

Amount of time deposits maturing in the second fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

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- Definition

Amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.12)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 9

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