Name:	msbi_FairValueGainsLossesRecognizedOnAssetsMeasuredOnNonRecurringBasis
Namespace Prefix:	msbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

N/A

No definition available.

Name:	msbi_FairValueGainsLossesRecognizedOnAssetsMeasuredOnNonRecurringBasisAbstract
Namespace Prefix:	msbi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The gains (losses) recognized on assets, impaired loans representing the difference between the carrying value and fair value measured on a non recurring basis.

No definition available.

Name:	msbi_FairValueGainsLossesRecognizedOnAssetsMeasuredOnNonRecurringBasisImpairedLoans
Namespace Prefix:	msbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The gains (losses) recognized on assets, other real estate owned representing the difference between the carrying value and fair value measured on a non recurring basis.

No definition available.

Name:	msbi_FairValueGainsLossesRecognizedOnAssetsMeasuredOnNonRecurringBasisOtherRealEstateOwned
Namespace Prefix:	msbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of gain (loss) from the difference between the sale price or salvage price and the book value of an asset that was sold or retired, and gain (loss) from the write down of assets from their carrying value to fair value.

No definition available.

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

The adjustment to the carrying value of the rights retained or purchased to service mortgages. These adjustments are made when the estimate of the fair value is changed. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 4
-Subparagraph (a)(6),(7)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122739-111746