FAIR VALUE MEASUREMENTS AND DISCLOSURES (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for selling costs (in hundredths)	6.00%msl_DiscountsForSellingCosts
Additional discount for taxes, insurance and maintenance costs (in hundredths)	4.00%
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period when new appraisals are received	28 days
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period when new appraisals are received	42 days
Recurring [Member]
Available-for-sale Securities [Abstract]
U.S. Government sponsored enterprises	10,227	$ 11,265
Obligations of state and political subdivisions	44,605	59,978
GSE mortgage-backed securities	109,103	145,965
Collateralized mortgage obligations: residential	60,839	70,887
Collateralized mortgage obligations: commercial	24,545	27,346
Other asset-backed securities	24,343	25,489
Collateralized debt obligation	1,218	735
Mutual funds	2,104
Recurring [Member] \| Level 1 [Member]
Available-for-sale Securities [Abstract]
U.S. Government sponsored enterprises	0	0
Obligations of state and political subdivisions	0	0
GSE mortgage-backed securities	0	0
Collateralized mortgage obligations: residential	0	0
Collateralized mortgage obligations: commercial	0	0
Other asset-backed securities	0	0
Collateralized debt obligation	0	0
Mutual funds	2,104
Recurring [Member] \| Level 2 [Member]
Available-for-sale Securities [Abstract]
U.S. Government sponsored enterprises	10,227	11,265
Obligations of state and political subdivisions	44,605	59,978
GSE mortgage-backed securities	109,103	145,965
Collateralized mortgage obligations: residential	60,839	70,887
Collateralized mortgage obligations: commercial	24,545	27,346
Other asset-backed securities	24,343	25,489
Collateralized debt obligation	1,218	735
Mutual funds	0
Recurring [Member] \| Level 3 [Member]
Available-for-sale Securities [Abstract]
U.S. Government sponsored enterprises	0	0
Obligations of state and political subdivisions	0	0
GSE mortgage-backed securities	0	0
Collateralized mortgage obligations: residential	0	0
Collateralized mortgage obligations: commercial	0	0
Other asset-backed securities	0	0
Collateralized debt obligation	0	0
Mutual funds	0
Nonrecurring [Member]
Assets and Liabilities measured on nonrecurring basis [Abstract]
Impaired loans	5,051	1,973
Other real estate	4,234	6,687
Nonrecurring [Member] \| Level 1 [Member]
Assets and Liabilities measured on nonrecurring basis [Abstract]
Impaired loans	0	0
Other real estate	0	0
Nonrecurring [Member] \| Level 2 [Member]
Assets and Liabilities measured on nonrecurring basis [Abstract]
Impaired loans	5,051	1,973
Other real estate	4,234	6,687
Nonrecurring [Member] \| Level 3 [Member]
Assets and Liabilities measured on nonrecurring basis [Abstract]
Impaired loans	0	0
Other real estate	0	$ 0

No definition available.

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Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

+ References

No definition available.

+ Details

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Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents securitized, pay-through debt securities collateralized by commercial real estate mortgage loans (mortgages) as of the balance sheet date which have been categorized as available-for-sale.

+ References

No definition available.

+ Details

Name:	msl_CollateralizedMortgageObligationsCommercialAvailableForSaleFairValueDisclosure
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents securitized, pay-through debt securities collateralized by residential real estate mortgage loans (mortgages) as of the balance sheet date which have been categorized as available-for-sale.

+ References

No definition available.

+ Details

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Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Commission rate discount for taxes, insurance and maintenance costs on sales with real estate agents.

+ References

No definition available.

+ Details

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Namespace Prefix:	msl_
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Balance Type:	na
Period Type:	duration

- Definition

Commission rate discount on sales with real estate agents.

+ References

No definition available.

+ Details

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Namespace Prefix:	msl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents impaired loan receivable as presented on the statement of financial position which may include impaired mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts, or any other loans which are due the Company as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	msl_ImpairedLoansFairValueDisclosure
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	msl_MutualFundsAvailableForSaleFairValueDisclosure
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period when new appraisals are typically received.

+ References

No definition available.

+ Details

Name:	msl_PeriodWhenNewAppraisalsAreReceived
Namespace Prefix:	msl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents bonds or similar securities issued by state, city, province, or local governments or their agencies in either the United States or a foreign country. Debt securities issued by state governments or provinces may include bond issuances of US state or foreign authorities. Debt securities issued by political subdivisions or US states may include debt issuances by county, borough, city, or municipal governments.

+ References

No definition available.

+ Details

Name:	msl_TradingInstrumentsObligationOfStateAndPoliticalSubdivisions
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

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Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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- Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Mortgage-Backed Securities

-URI http://asc.fasb.org/extlink&oid=6517959

+ Details

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

- Definition

Fair value portion of other assets.

+ References

No definition available.

+ Details

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

- Details

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- Details

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- Details

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