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Allowance for Credit Losses and Credit Quality of Loans (Details) - USD ($) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Allowance for Credit Losses [Abstract] |  |  |  |  |  |
Allowance for credit losses | [1] | $ 110,000 |  |  |  |
Allowance for credit losses |  |  | $ 72,965 | [1] | $ 72,505 | $ 69,500
Retained earnings |  | 749,056 | $ 696,214 |  |  |
Loans purchased with credit deterioration |  | $ 0 |  |  |  |
Percentage of allowance of credit losses |  | 1.47% | 1.02% |  |  |
Provision for loan and lease losses |  | $ 51,100 | $ 25,400 |  |  |
ASU 2016-13 [Member] |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |
Allowance for credit losses |  | 110,000 | 75,999 |  |  |
ASU 2016-13 [Member] | Loans [Member] |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |
Allowance for credit losses |  | 3,000 |  |  |  |
Retained earnings |  | (2,300) |  |  |  |
Deferred tax asset |  | 700 |  |  |  |
ASU 2016-13 [Member] | Accrued Interest Receivable [Member] |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |
Allowance for credit losses |  | 600 |  |  |  |
AIR on loans |  | $ 23,700 |  |  |  |
Write-off of uncollectible interest period |  | 120 days |  |  |  |
Consumer Loans [Member] |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |
Allowance for credit losses |  |  | 35,647 |  | $ 37,178 | $ 36,830
Amount of loans purchased |  | $ 51,900 |  |  |  |
Discount on loans purchased |  | 1.00% |  |  |  |
Allowance for credit losses on loans purchased |  | $ 3,600 |  |  |  |
Consumer Loans [Member] | ASU 2016-13 [Member] |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |
Allowance for credit losses |  | $ 37,803 | $ 32,122 |  |  |
[1] | Beginning January 1, 2020, calculation is based on current expected loss methodology. Prior to January 1, 2020, calculation was based on incurred loss methodology.

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- Definition Allowance for credit losses as a percentage of financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement. + References No definition available. + Details
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- Definition The write-off period of uncollectible interest of delinquent loans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Amount of loans purchased with credit deterioration during the period. + References No definition available. + Details
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- Definition Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was 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 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 (b)(2) -URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544 + Details
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- Definition Amount, after allowance for credit loss, of accrued interest on financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3A -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL120267960-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=121599878&loc=SL120267845-210446 + Details
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- Definition Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 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 (b)(1)(ii) -URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L.1) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707 + Details
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