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ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands |  | 9 Months Ended
--- | --- | ---
Dec. 31, 2019 | Sep. 30, 2020
Loans [Abstract] |  |
Accrued interest receivable on loans |  | $ 23,800
Number of days past due for loans to be placed on nonaccrual status |  | 90 days
Number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property |  | 90 days
Contract Balances |  |
Accounts receivable | $ 26,800 | $ 28,500
Unbilled fee revenue | 7,500 | 8,300
Unearned revenue | 1,800 | 2,000
New Accounting Pronouncements |  |
Retained earnings | 882,851 | 936,273
Allowance for Credit Losses - Debt Securities |  |
Accrued interest receivable on available-for-sale debt securities |  | $ 14,200
Consumer Installment Loans [Member] |  |
Loans [Abstract] |  |
Number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property |  | 90 days
Consumer Mortgage [Member] |  |
Loans [Abstract] |  |
Number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property |  | 180 days
Consumer Mortgage [Member] | Minimum [Member] |  |
New Accounting Pronouncements |  |
Typical contract term |  | 10 years
Consumer Mortgage [Member] | Maximum [Member] |  |
New Accounting Pronouncements |  |
Typical contract term |  | 30 years
Home Equity [Member] | Maximum [Member] |  |
New Accounting Pronouncements |  |
Typical contract term |  | 30 years
Topic ASC 326 | Cumulative Effect Adjustment |  |
New Accounting Pronouncements |  |
Retained earnings | 1,100 |
Increase in allowance for credit losses | 1,400 |
Adjustment to loans | 3,100 |
Increase in other liabilities | 600 |
Addition to allowance for credit losses | $ 3,100 |

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- Definition Refers to the number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property, 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 The number of days according to the entity's policy that a loan must be past due before being placed on nonaccrual status, 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, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130531-203044 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130533-203044 + Details
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