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Loans and allowance for credit losses - Changes in Value of Accretable Yield for PCI Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
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Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] |  |  |
Accretion |  | $ 3,080 | $ 6,030
Purchased Credit Impaired |  |  |
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] |  |  |
Balance at the beginning of period | $ (14,862) |  | (16,587)
Additions through business combinations | 0 |  | (1,167)
Principal reductions and other reclassifications from nonaccretable difference | (150) |  | 100
Accretion | 1,583 |  | 5,471
Changes in expected cash flows | 110 |  | (1,136)
Balance at end of period | $ (13,319) |  | $ (13,319)

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- Definition Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Business Combinations + References No definition available. + Details
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- Definition Certain loans acquired in transfer not accounted for as debt securities accretable yield other changes. + References No definition available. + Details
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- Definition certain loans acquired in transfer not accounted for as debt securities accretable yield principal repayment and reclassification from nonaccretable difference. + References No definition available. + Details
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- Definition Amount 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=121585399&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 Amount of accretion recognized for 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=121585399&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 A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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