composition of loans receivable by delinquency status (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Loans Receivable Delinquency Status Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family	$ 352,735	$ 349,382
Residential 5+ multifamily	36,111	36,197
Construction of residential 1-4 family	12,251	8,814
Home equity lines of credit	24,923	27,522
Residential real estate	426,020	421,915
Commercial	310,574	307,927
Construction of commercial	41,983	31,722
Commercial real estate	352,557	339,649
Farm land	2,940	2,594
Vacant land	13,006	14,079
Real estate secured	794,523	778,237
Commercial and industrial	218,037	224,496
Municipal	18,341	21,512
Consumer	9,539	7,677
Loans receivable, gross	1,040,440	1,031,922
Loans Receivable Delinquency Status Period Two [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family	128	1,419
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit	182	157
Residential real estate	310	1,576
Commercial	1,538	1,855
Construction of commercial
Commercial real estate	1,538	1,855
Farm land		154
Vacant land
Real estate secured	1,848	3,585
Commercial and industrial	674	2,148
Municipal
Consumer	3	10
Loans receivable, gross	2,525	5,743
Loans Receivable Delinquency Status Period Three [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family	457	308
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit	46	9
Residential real estate	503	317
Commercial	31	530
Construction of commercial
Commercial real estate	31	530
Farm land	139	450
Vacant land
Real estate secured	673	1,297
Commercial and industrial		457
Municipal
Consumer	1
Loans receivable, gross	674	1,754
Loans Receivable Delinquency Status Period Four [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family		673
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit	7
Residential real estate	7	673
Commercial	503	95
Construction of commercial
Commercial real estate	503	95
Farm land
Vacant land
Real estate secured	510	768
Commercial and industrial		1
Municipal
Consumer
Loans receivable, gross	510	769
Loans Receivable Delinquency Status Period Five [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family	332	219
Residential 5+ multifamily	861	861
Construction of residential 1-4 family
Home equity lines of credit	104	116
Residential real estate	1,297	1,196
Commercial		434
Construction of commercial
Commercial real estate		434
Farm land	450
Vacant land
Real estate secured	1,747	1,630
Commercial and industrial	46	46
Municipal
Consumer
Loans receivable, gross	1,793	1,676
Loans Receivable Delinquency Status Period Six [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family	917	2,619
Residential 5+ multifamily	861	861
Construction of residential 1-4 family
Home equity lines of credit	339	282
Residential real estate	2,117	3,762
Commercial	2,072	2,914
Construction of commercial
Commercial real estate	2,072	2,914
Farm land	589	604
Vacant land
Real estate secured	4,778	7,280
Commercial and industrial	720	2,652
Municipal
Consumer	4	10
Loans receivable, gross	5,502	9,942
Loans Receivable Delinquency Accrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit
Residential real estate
Commercial
Construction of commercial
Commercial real estate
Farm land
Vacant land
Real estate secured
Commercial and industrial	11	12
Municipal
Consumer
Loans receivable, gross	11	12
Loans Receivable Delinquency Non Accrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential 1-4 family	1,544	1,508
Residential 5+ multifamily	861	861
Construction of residential 1-4 family
Home equity lines of credit	147	154
Residential real estate	2,552	2,523
Commercial	2,000	2,544
Construction of commercial
Commercial real estate	2,000	2,544
Farm land	594	158
Vacant land	35	37
Real estate secured	5,181	5,262
Commercial and industrial	347	374
Municipal
Consumer
Loans receivable, gross	$ 5,528	$ 5,636

No definition available.

Name:	SAL_InventoryRealEstateCommercial
Namespace Prefix:	SAL_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	SAL_InventoryRealEstateCommercialAndIndustrial
Namespace Prefix:	SAL_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	SAL_InventoryRealEstateCommercialRealEstate
Namespace Prefix:	SAL_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	SAL_InventoryRealEstateFarmLand
Namespace Prefix:	SAL_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	SAL_InventoryRealEstateMultifamily
Namespace Prefix:	SAL_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

The fair value as of the balance sheet date of firm holdings in fixed income obligations issued by state and local governments and authorities. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 320
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969

+ Details

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

- Definition

The net carrying amount as of the balance sheet date of the sum of the various components of an operative builder's inventory, including finished homes. Operative builders primarily consist of entities that develop land, construct residential homes and commercial and industrial buildings thereon, and sell them to home buyers and operators of the commercial and industrial properties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Total of (1) improvements, (2) held-for-sale, (3) land and land under development, (4) construction-in-process, (5) mortgage loans held-in-inventory, and (6) other real estate investments which are considered inventory due to being held for sale or disposition.

+ References

No definition available.

+ Details

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

- Definition

Cost of real estate projects incurred for projects for eventual sale or transfer (condominium or time share projects, vacation clubs).

+ References

No definition available.

+ Details

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

- Definition

Carrying amount as of the balance sheet date, net of valuation allowances and impairment losses, of costs of land expected to be developed in the near term plus capitalized costs of development, for purposes of selling completed units to home buyers or commercial or industrial entities..

+ References

+ Details

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

- Definition

Represents mortgage loans held in inventory primarily for sale to others (third parties, businesses, legal entities) in the ordinary course of business.

+ References

No definition available.

+ Details

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

- Definition

Amount of investment in certain other real estate investments not specifically identified elsewhere in the existing taxonomy.

+ References

No definition available.

+ Details

Name:	us-gaap_InventoryRealEstateOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524

+ Details

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

- Definition

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(c))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyStatusCurrentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyStatusPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyStatusPeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyStatusPeriodFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyStatusPeriodFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyStatusPeriodSixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyAccrualMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis=SAL_LoansReceivableDelinquencyNonAccrualMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: