LOANS, Loans and Allowance for Loan Losses Impairment Evaluations (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	$ 507	$ 777
Ending balance: collectively evaluated for impairment	19,610	19,908
Ending balance	20,117	20,685	$ 19,200	$ 17,263
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	13,733	15,085
Ending balance: collectively evaluated for impairment	1,662,831	1,651,362
Total loans	1,676,564	1,666,447
Commercial real estate mortgage loans to warrant information from management, minimum	$ 750
Loans to value ratio for originating residential mortgage and home equity loans, maximum	80.00%
Owner-occupied Real Estate [Member]
Loan balances [Abstract]
Commercial real estate mortgage loans to warrant information from management, minimum	$ 750
Commercial and Industrial [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	4	0
Ending balance: collectively evaluated for impairment	2,128	1,875
Ending balance	2,132	1,875	1,560	2,615
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	3,592	2,872
Ending balance: collectively evaluated for impairment	185,818	186,897
Total loans	189,410	189,769
Commercial Real Estate [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	8,030	7,019
Ending balance	8,030	7,019	6,777	6,572
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	3,371	4,334
Ending balance: collectively evaluated for impairment	728,615	692,453
Total loans	731,986	696,787
Multifamily [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	3,623	4,688
Ending balance	3,623	4,688	4,018	2,159
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	402,935	426,549
Total loans	402,935	426,549
Mixed Use Commercial [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	730	766
Ending balance	730	766	261	54
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	78,807	78,787
Total loans	$ 78,807	78,787
Percentage of commercial rents	50.00%
Real Estate Construction [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	$ 0	0
Ending balance: collectively evaluated for impairment	560	386
Ending balance	560	386	383	88
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	41,028	37,233
Total loans	41,028	37,233
Residential Mortgages [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	305	559
Ending balance: collectively evaluated for impairment	1,696	1,917
Ending balance	2,001	2,476	3,027	2,463
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	4,981	5,817
Ending balance: collectively evaluated for impairment	180,131	180,496
Total loans	185,112	186,313
Home Equity [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	172	170
Ending balance: collectively evaluated for impairment	343	469
Ending balance	515	639	709	745
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	1,579	1,683
Ending balance: collectively evaluated for impairment	40,840	43,268
Total loans	42,419	44,951
Consumer [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	26	48
Ending balance: collectively evaluated for impairment	36	58
Ending balance	62	106
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	210	379
Ending balance: collectively evaluated for impairment	4,657	5,679
Total loans	4,867	6,058
Unallocated [Member]
Allowance for loan losses [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	2,464	2,730
Ending balance	2,464	2,730	$ 2,299	$ 2,326
Loan balances [Abstract]
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	0	0
Total loans	$ 0	$ 0

No definition available.

Name:	scnb_LoanBalancesAbstract
Namespace Prefix:	scnb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum loans to value ratio for originating loans.

+ References

No definition available.

+ Details

Name:	scnb_LoansToValueRatioForOriginatingLoansMaximum
Namespace Prefix:	scnb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Refers to minimum loans to warrant information from management.

+ References

No definition available.

+ Details

Name:	scnb_LoansToWarrantInformationFromManagementMinimum
Namespace Prefix:	scnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Refers to the percentage of total commercial rents.

+ References

No definition available.

+ Details

Name:	scnb_PercentageOfCommercialRents
Namespace Prefix:	scnb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

+ Details

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

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5074-111524

+ Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=scnb_OwnerOccupiedRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=scnb_CommercialAndIndustrialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_MultifamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=scnb_MixedUseCommercialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=scnb_RealEstateConstructionPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_UnallocatedFinancingReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: