LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for loan losses
Balance at the beginning of the period	$ 27,609	$ 32,227	$ 39,889
Provision charged to expense	1,500us-gaap_ProvisionForLoanAndLeaseLosses	4,534us-gaap_ProvisionForLoanAndLeaseLosses	9,850us-gaap_ProvisionForLoanAndLeaseLosses
Losses charged off	(11,018)	(12,502)	(22,332)
Recoveries	5,159	3,350	4,820
Balance at the end of the period	23,250	27,609	32,227
Allowance for loan losses
Ending Balance individually evaluated for impairment	1,050	1,287	3,217
Ending Balance collectively evaluated for impairment	22,200	26,322
Total ending allowance balance	23,250	27,609	32,227
Loans
Ending Balance individually evaluated for impairment	36,309	33,122
Ending Balance collectively evaluated for impairment	1,921,456	1,638,804
Total ending loan balance excluding accrued interest	1,957,765	1,671,926
Accrued interest	5,605us-gaap_InterestReceivable	5,043us-gaap_InterestReceivable
Allowance that includes a probability of default for subject loans	2,426msfg_AllowanceForLoansReserve	5,783msfg_AllowanceForLoansReserve
Commercial
Allowance for loan losses
Balance at the beginning of the period	3,291	3,894	5,562
Provision charged to expense	(1,204)	208	(265)
Losses charged off	(241)	(1,152)	(1,946)
Recoveries	1,131	341	543
Balance at the end of the period	2,977	3,291	3,894
Allowance for loan losses
Ending Balance individually evaluated for impairment	162	13
Ending Balance collectively evaluated for impairment	2,815	3,278
Total ending allowance balance	2,977	3,291	3,894
Loans
Ending Balance individually evaluated for impairment	705	300
Ending Balance collectively evaluated for impairment	321,725	210,401
Total ending loan balance excluding accrued interest	322,430	210,701
Commercial Real Estate
Allowance for loan losses
Balance at the beginning of the period	20,210	24,157	30,476
Provision charged to expense	(1,284)	1,319	4,802
Losses charged off	(5,583)	(6,353)	(13,553)
Recoveries	2,262	1,087	2,432
Balance at the end of the period	15,605	20,210	24,157
Allowance for loan losses
Ending Balance individually evaluated for impairment	705	1,167
Ending Balance collectively evaluated for impairment	14,900	19,043
Total ending allowance balance	15,605	20,210	24,157
Loans
Ending Balance individually evaluated for impairment	24,722	21,240
Ending Balance collectively evaluated for impairment	855,146	745,769
Total ending loan balance excluding accrued interest	879,868	767,009
Residential
Allowance for loan losses
Balance at the beginning of the period	3,409	3,180	2,972
Provision charged to expense	1,977	1,928	3,490
Losses charged off	(2,295)	(2,349)	(3,547)
Recoveries	410	650	265
Balance at the end of the period	3,501	3,409	3,180
Allowance for loan losses
Ending Balance individually evaluated for impairment	183	105
Ending Balance collectively evaluated for impairment	3,318	3,304
Total ending allowance balance	3,501	3,409	3,180
Loans
Ending Balance individually evaluated for impairment	10,662	10,797
Ending Balance collectively evaluated for impairment	698,833	637,213
Total ending loan balance excluding accrued interest	709,495	648,010
Consumer
Allowance for loan losses
Balance at the beginning of the period	699	996	879
Provision charged to expense	2,011	1,079	1,823
Losses charged off	(2,899)	(2,648)	(3,286)
Recoveries	1,356	1,272	1,580
Balance at the end of the period	1,167	699	996
Allowance for loan losses
Ending Balance individually evaluated for impairment		2
Ending Balance collectively evaluated for impairment	1,167	697
Total ending allowance balance	1,167	699	996
Loans
Ending Balance individually evaluated for impairment	220	785
Ending Balance collectively evaluated for impairment	45,752	45,421
Total ending loan balance excluding accrued interest	$ 45,972	$ 46,206

Amount of loans that have been allowance reserve for credit loss.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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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.

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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.

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Amount of expense related to estimated loss from loan and lease transactions.

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