Deferred loan origination fees incurred at the end of period.

No definition available.

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Namespace Prefix:	nvsl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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Namespace Prefix:	nvsl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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=49124121&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=49124121&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 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

Amount after allowance and 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 and loans held for sale.

+ 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=28367877&loc=d3e4428-111522

Reference 2: 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)

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

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Balance Type:
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- Details

Name:	us-gaap_FinancialInstrumentAxis=nvsl_OneToFourFamilyMember
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- Details

Name:	us-gaap_FinancialInstrumentAxis=nvsl_MultiFamilyAndCommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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- Details

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Data Type:	na
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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_FinancialInstrumentAxis=nvsl_OtherConsumerMember
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LOANS RECEIVABLE (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Loans Receivable [Line Items]
Total loans	$ 385,695	$ 369,325	$ 364,255
Allowance for loan losses	4,615	6,023	$ 6,971	$ 9,891
Deferred loan origination fees	72	43
Loans receivable, net	381,008	363,259
Commercial business loans [Member]
Loans Receivable [Line Items]
Total loans	24,896	25,801
Real Estate [Member]
Loans Receivable [Line Items]
Total loans	320,611	306,680
Real Estate [Member] \| One to four family [Member]
Loans Receivable [Line Items]
Total loans	179,603	180,739
Real Estate [Member] \| Multi-Family and Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total loans	137,581	122,526
Real Estate [Member] \| Construction Loans [Member]
Loans Receivable [Line Items]
Total loans	3,427	3,415
Consumer Loan [Member]
Loans Receivable [Line Items]
Total loans	40,188	36,844
Consumer Loan [Member] \| Home Equity Line of Credit [Member]
Loans Receivable [Line Items]
Total loans	33,246	28,700
Consumer Loan [Member] \| Other consumer [Member]
Loans Receivable [Line Items]
Total loans	$ 6,942	$ 8,144