Loans and Allowance for Loan Losses (Details 2) (USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Impaired and Restructured Loans with or with no related allowance recorded
Unpaid Principal Balance With no related allowance recorded	$ 11,897,350	$ 9,349,665
Recorded Investment With no related allowance recorded	8,499,517	6,030,349
Average Recorded Investment With no related allowance recorded	9,315,986	6,966,609
Interest Income Recognized With no related allowance recorded	2,391,394	2,132,439
Impaired and Restructured Loans with or with an allowance recorded
Unpaid Principal Balance With an allowance recorded	3,198,096	5,649,239
Recorded Investment With an allowance recorded	3,003,774	5,467,930
Related Allowance	2,018,193	1,998,658
Average Recorded Investment With an allowance recorded	3,051,730	5,511,550
Interest Income Recognized With an allowance recorded	548,135	882,197
Grand Total of Impaired and Restructured Loans
Unpaid Principal balance	15,095,446	14,998,904
Recorded Investment	11,503,291	11,498,279
Average Recorded Investment	12,367,716	12,478,159
Interest Income Recognized	2,939,529	3,014,636
Commercial
Impaired and Restructured Loans with or with no related allowance recorded
Unpaid Principal Balance With no related allowance recorded	296,350	296,350
Recorded Investment With no related allowance recorded	131,749	140,575
Average Recorded Investment With no related allowance recorded	146,596	150,913
Interest Income Recognized With no related allowance recorded	53,216	51,151
Impaired and Restructured Loans with or with an allowance recorded
Unpaid Principal Balance With an allowance recorded	1,360,535	1,360,535
Recorded Investment With an allowance recorded	1,249,849	1,251,462
Related Allowance	1,249,849	1,251,462
Average Recorded Investment With an allowance recorded	1,284,226	1,287,204
Interest Income Recognized With an allowance recorded	183,244	168,739
Commercial Real Estate
Impaired and Restructured Loans with or with no related allowance recorded
Unpaid Principal Balance With no related allowance recorded	11,281,464	8,733,779
Recorded Investment With no related allowance recorded	8,056,896	5,578,231
Average Recorded Investment With no related allowance recorded	8,854,164	6,499,933
Interest Income Recognized With no related allowance recorded	2,273,039	2,019,907
Impaired and Restructured Loans with or with an allowance recorded
Unpaid Principal Balance With an allowance recorded	908,269	3,355,954
Recorded Investment With an allowance recorded	825,063	3,287,773
Related Allowance	257,904	169,243
Average Recorded Investment With an allowance recorded	838,568	3,295,385
Interest Income Recognized With an allowance recorded	220,680	363,187
Consumer Real Estate
Impaired and Restructured Loans with or with no related allowance recorded
Unpaid Principal Balance With no related allowance recorded	319,536	319,536
Recorded Investment With no related allowance recorded	310,872	311,543
Average Recorded Investment With no related allowance recorded	315,226	315,763
Interest Income Recognized With no related allowance recorded	65,139	61,381
Impaired and Restructured Loans with or with an allowance recorded
Unpaid Principal Balance With an allowance recorded	879,292	882,750
Recorded Investment With an allowance recorded	879,419	879,252
Related Allowance	460,997	528,510
Average Recorded Investment With an allowance recorded	879,389	879,391
Interest Income Recognized With an allowance recorded	137,741	344,262
Consumer Other
Impaired and Restructured Loans with or with no related allowance recorded
Unpaid Principal Balance With no related allowance recorded
Recorded Investment With no related allowance recorded
Average Recorded Investment With no related allowance recorded
Interest Income Recognized With no related allowance recorded
Impaired and Restructured Loans with or with an allowance recorded
Unpaid Principal Balance With an allowance recorded	50,000	50,000
Recorded Investment With an allowance recorded	49,443	49,443
Related Allowance	49,443	49,443
Average Recorded Investment With an allowance recorded	49,547	49,570
Interest Income Recognized With an allowance recorded	$ 6,470	$ 6,009

Name:	bksc_GrandTotalOfImpairedAndRestructuredLoansAbstract
Namespace Prefix:	bksc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	bksc_ImpairedAndRestructuredLoansWithOrWithAllowanceRecordedAbstract
Namespace Prefix:	bksc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	bksc_ImpairedFinancingReceivableithWithOrWithNoRelatedAllowanceRecordedAbstract
Namespace Prefix:	bksc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6951948&loc=d3e18845-111554

+ Details

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

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5258-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableRelatedAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953550-111524

+ Details

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

- Definition

Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Definition

Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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