This line item represents the interest received on nonaccrual loans.

No definition available.

Name:	msl_InterestReceivedOnNonaccrualLoans
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5111-111524

+ Details

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

- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18794-111554

+ Details

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

- Details

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

- Details

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- Details

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

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=msl_ResidentialConstructionMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialPrimeFinancingReceivableMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CreditCardReceivablesMember
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Data Type:	na
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- Details

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

Credit Quality of Loans and Allowance for Loan Losses - Nonaccrual Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	$ 53,714		$ 50,051
Interest lost on nonaccrual loans	757	$ 342
Interest received on nonaccrual loans	59	$ 11
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	24,900		27,705
Commercial real estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	35		37
Commercial real estate - other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	25,951		19,907
Residential - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	0		0
Residential - prime
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	2,322		1,998
Consumer - credit card
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	0		0
Consumer - other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	506		404
Lease financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	0		0
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on nonaccrual status	$ 0		$ 0