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Income Taxes - Unrecognized Tax Benefits (Details) - First Midwest - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] |  |  |
Balance at beginning of period | $ 11,007 | $ 0 | $ 0
Additions for acquired uncertain tax positions | 0 | 14,897 | 0
Additions based on tax positions related to prior years | 60 | 0 | 0
Reductions for tax positions relating to prior years | 0 | (2,751) | 0
Reductions due to statute of limitations expiring | (1,112) | (1,139) | 0
Balance at end of period | $ 9,955 | $ 11,007 | $ 0

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- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 15A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-15A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 10B -Publisher FASB -URI https://asc.fasb.org//1943274/2147482525/740-10-45-10B + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 15A -Subparagraph (a)(4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-15A + Details
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