Fair Value Measurements (Details 2) (Impaired Loans)	3 Months Ended
Mar. 31, 2013
Impaired Loans
Valuation technique	Discounted Appraisals
Significant unobservable inputs	Collateral Discounts
General range of significant input values, minimum	0.00%
General range of significant input values, maximum	25.00%

The maximum general range of significant unobservable input values.

No definition available.

Name:	bksc_GeneralRangeOfSignificantInputValuesMaximum
Namespace Prefix:	bksc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum general range of significant unobservable input values.

+ References

No definition available.

+ Details

Name:	bksc_GeneralRangeOfSignificantInputValuesMinimum
Namespace Prefix:	bksc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of significant assumptions used by management to measure fair value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611

+ Details

Name:	us-gaap_FairValueMeasurementsSignificantAssumptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the inputs and valuation technique(s) used to measure fair value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementsValuationTechniques
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration