Credit Quality of Loans and Allowance for Loan Losses, Impaired Loans by Class of Loans (Details) (USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
With no related allowance recorded [Abstract]
Recorded Investment	$ 5,849,000		$ 3,034,000
Unpaid Principal Balance	5,932,000		3,117,000
Related Allowance	0		0
Average Recorded Investment	4,441,000		3,103,000
Interest Income Recognized	17,000		32,000
With an allowance recorded [Abstract]
Recorded Investment	6,908,000		7,513,000
Unpaid Principal Balance	7,056,000		7,661,000
Related Allowance	1,645,000		2,741,000
Average Recorded Investment	7,210,000		4,533,000
Interest Income Recognized	1,000		262,000
Totals [Abstract]
Recorded Investment	12,757,000		10,547,000
Unpaid Principal Balance	12,988,000		10,778,000
Related Allowance	1,645,000		2,741,000
Average Recorded Investment	11,651,000		7,636,000
Interest Income Recognized	18,000		294,000
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	12,894,000		10,701,000
Interest lost on nonaccrual loans	342,000	118,000
Interest received on nonaccrual loans	11,000msl_InterestReceivedOnNonaccrualLoans	88,000msl_InterestReceivedOnNonaccrualLoans
Commercial, Financial and Agricultural [Member]
With no related allowance recorded [Abstract]
Recorded Investment	407,000		438,000
Unpaid Principal Balance	490,000		521,000
Related Allowance	0		0
Average Recorded Investment	422,000		554,000
Interest Income Recognized	0		0
With an allowance recorded [Abstract]
Recorded Investment	2,020,000		2,218,000
Unpaid Principal Balance	2,134,000		2,333,000
Related Allowance	737,000		1,010,000
Average Recorded Investment	2,119,000		1,394,000
Interest Income Recognized	0		35,000
Totals [Abstract]
Related Allowance	737,000		1,010,000
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	2,413,000		2,642,000
Commercial Real Estate - Construction [Member]
With no related allowance recorded [Abstract]
Recorded Investment	43,000		54,000
Unpaid Principal Balance	43,000		54,000
Related Allowance	0		0
Average Recorded Investment	49,000		58,000
Interest Income Recognized	0		0
With an allowance recorded [Abstract]
Recorded Investment			0
Unpaid Principal Balance			0
Related Allowance			0
Average Recorded Investment			19,000
Interest Income Recognized			0
Totals [Abstract]
Related Allowance			0
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	43,000		54,000
Commercial Real Estate - Other [Member]
With no related allowance recorded [Abstract]
Recorded Investment	3,852,000		1,921,000
Unpaid Principal Balance	3,852,000		1,921,000
Related Allowance	0		0
Average Recorded Investment	2,886,000		1,885,000
Interest Income Recognized	12,000		17,000
With an allowance recorded [Abstract]
Recorded Investment	4,125,000		4,467,000
Unpaid Principal Balance	4,125,000		4,467,000
Related Allowance	645,000		1,484,000
Average Recorded Investment	4,296,000		2,416,000
Interest Income Recognized	0		220,000
Totals [Abstract]
Related Allowance	645,000		1,484,000
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	8,012,000		6,429,000
Consumer - Other [Member]
With no related allowance recorded [Abstract]
Recorded Investment	56,000		78,000
Unpaid Principal Balance	56,000		78,000
Related Allowance	0		0
Average Recorded Investment	67,000		72,000
Interest Income Recognized	0		0
With an allowance recorded [Abstract]
Recorded Investment	349,000		299,000
Unpaid Principal Balance	363,000		313,000
Related Allowance	206,000		179,000
Average Recorded Investment	324,000		252,000
Interest Income Recognized	1,000		4,000
Totals [Abstract]
Related Allowance	206,000		179,000
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	408,000		382,000
Residential - Prime [Member]
With no related allowance recorded [Abstract]
Recorded Investment	1,057,000		543,000
Unpaid Principal Balance	1,057,000		543,000
Related Allowance	0		0
Average Recorded Investment	800,000		534,000
Interest Income Recognized	5,000		15,000
With an allowance recorded [Abstract]
Recorded Investment	414,000		529,000
Unpaid Principal Balance	434,000		548,000
Related Allowance	57,000		68,000
Average Recorded Investment	471,000		452,000
Interest Income Recognized	0		3,000
Totals [Abstract]
Related Allowance	57,000		68,000
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	1,585,000		1,194,000
Lease Financing Receivable [Member]
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	0		0
Other Loans [Member]
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	0		0
Commercial Total [Member]
With an allowance recorded [Abstract]
Related Allowance	1,382,000		2,494,000
Totals [Abstract]
Recorded Investment	10,447,000		9,098,000
Unpaid Principal Balance	10,644,000		9,296,000
Related Allowance	1,382,000		2,494,000
Average Recorded Investment	9,772,000		6,326,000
Interest Income Recognized	12,000		272,000
Consumer Total [Member]
With an allowance recorded [Abstract]
Related Allowance	206,000		179,000
Totals [Abstract]
Recorded Investment	405,000		377,000
Unpaid Principal Balance	419,000		391,000
Related Allowance	206,000		179,000
Average Recorded Investment	391,000		324,000
Interest Income Recognized	1,000		4,000
Residential Total [Member]
With an allowance recorded [Abstract]
Related Allowance	57,000		68,000
Totals [Abstract]
Recorded Investment	1,905,000		1,072,000
Unpaid Principal Balance	1,925,000		1,091,000
Related Allowance	57,000		68,000
Average Recorded Investment	1,488,000		986,000
Interest Income Recognized	5,000		18,000
Consumer - Credit Card [Member]
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	0		0
Residential Construction [Member]
With no related allowance recorded [Abstract]
Recorded Investment	434,000
Unpaid Principal Balance	434,000
Related Allowance	0
Average Recorded Investment	217,000
Interest Income Recognized	0
Loans on Nonaccrual Status [Abstract]
Loans on Nonaccrual Status	$ 433,000		$ 0

Amount of allowance for credit losses related to recorded investment with no related allowance recorded.

No definition available.

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This line item represents the interest received on nonaccrual loans.

+ References

No definition available.

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- 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

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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-Publisher FASB

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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

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Amount of interest income, recognized on cash basis, on financing receivables, for which there is no related allowance for credit losses and are recognized as impaired.

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Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

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Amount of interest income on financing receivables, for which there is a related allowance for credit losses, recognized on a cash-basis method of accounting that the financing receivables were impaired.

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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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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).

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