XML 54 R43.htm IDEA: XBRL DOCUMENT
v3.25.2

INVESTMENT SECURITIES - Classified (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Investment securities available for sale |  |
Total available for sale securities | $ 1,460,020 | $ 1,314,790
Gross unrealized gains | 4,125 | 5,142
Gross unrealized losses | (99,944) | (112,358)
Fair value | 1,364,201 | 1,207,574
Adjustment | 1,600 | 1,900
U.S. Treasury securities |  |
Investment securities available for sale |  |
Total available for sale securities | 1,000 |
Gross unrealized gains | 0 |
Gross unrealized losses | 0 |
Fair value | 1,000 |
U.S. government sponsored entities and U.S. agency securities |  |
Investment securities available for sale |  |
Total available for sale securities | 26,350 | 21,655
Gross unrealized gains | 34 | 25
Gross unrealized losses | (1,284) | (1,539)
Fair value | 25,100 | 20,141
Mortgage-backed securities - agency |  |
Investment securities available for sale |  |
Total available for sale securities | 1,088,322 | 938,513
Gross unrealized gains | 2,102 | 3,411
Gross unrealized losses | (84,085) | (94,868)
Fair value | 1,006,339 | 847,056
Mortgage-backed securities - non-agency |  |
Investment securities available for sale |  |
Total available for sale securities | 96,787 | 103,051
Gross unrealized gains | 1,428 | 1,410
Gross unrealized losses | (3,027) | (3,449)
Fair value | 95,188 | 101,012
Asset-backed student loans |  |
Investment securities available for sale |  |
Total available for sale securities | 47,675 | 50,007
Gross unrealized gains | 38 | 66
Gross unrealized losses | (312) | (100)
Fair value | 47,401 | 49,973
State and municipal securities |  |
Investment securities available for sale |  |
Total available for sale securities | 75,176 | 75,597
Gross unrealized gains | 246 | 96
Gross unrealized losses | (6,311) | (6,632)
Fair value | 69,111 | 69,061
Collateralized loan obligations |  |
Investment securities available for sale |  |
Total available for sale securities | 39,155 | 40,365
Gross unrealized gains | 86 | 92
Gross unrealized losses | (29) | (7)
Fair value | 39,212 | 40,450
Corporate securities |  |
Investment securities available for sale |  |
Total available for sale securities | 85,555 | 85,602
Gross unrealized gains | 191 | 42
Gross unrealized losses | (4,896) | (5,763)
Fair value | $ 80,850 | $ 79,881

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, in portfolio layer hedging relationship. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 181 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-181 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4EEE -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4EEE + Details
Name: | us-gaap_HedgedAssetFairValueHedgeLastOfLayerCumulativeIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=msbi_AgencyMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=msbi_NonagencyMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=msbi_StudentLoanAssetBackedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CollateralizedLoanObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=msbi_CorporateDebtAndEquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |