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Acquisition - Carrying Value of Acquired Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Mar. 31, 2022 | Dec. 31, 2021
Business Acquisition [Line Items] |  |
Book value of loans acquired | $ 1,550,180 | $ 1,635,802
Accretion recorded on acquired loans year to date | 2,416 | 966
West Suburban Bancorp, Inc |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 1,442,906 | 1,521,161
Abc Bank |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 62,438 | 68,783
Talmer Bank |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 44,836 | 45,858
PCI |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 93,135 | 106,956
Accretion recorded on acquired loans year to date | 400 | 401
PCI | West Suburban Bancorp, Inc |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 88,601 | 102,409
PCI | Abc Bank |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 4,534 | 4,547
Non-PCI |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 1,457,045 | 1,528,846
Accretion recorded on acquired loans year to date | 2,016 | 565
Non-PCI | West Suburban Bancorp, Inc |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 1,354,305 | 1,418,752
Non-PCI | Abc Bank |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | 57,904 | 64,236
Non-PCI | Talmer Bank |  |
Business Acquisition [Line Items] |  |
Book value of loans acquired | $ 44,836 | $ 45,858

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- Definition Amount of increase (decrease) of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 15 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=123409700&loc=d3e13503-111538 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544 + Details
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- Definition The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 15 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=123409700&loc=d3e13503-111538 + Details
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