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Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | --- | ---
Item Effected |  |  |  |
Cumulative effect adjustment to retained earnings | $ 930,670 | $ 848,636 | $ 763,590 | $ 718,537
Financing Receivable, Allowance for Credit Loss | 140,654 | 111,254 | 100,469 | 94,883
Unfunded loan commitments |  | 3,172 |  |
Allowance for credit losses including off-balance sheet credit loss liability |  | 114,426 |  |
Commercial and agricultural |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 22,229 | 23,671 | 17,063 | 16,228
Auto and light truck |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 28,926 | 14,400 | 14,689 | 10,103
Medium and heavy duty truck |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 6,400 | 4,612 | 4,303 | 4,844
Aircraft |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 31,058 |  |
Construction equipment |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 19,166 | 14,120 | 10,922 | 9,343
Commercial real estate |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 22,758 | 18,350 | 15,705 | 14,792
Residential real estate and home equity |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 5,374 | 3,609 | 3,425 | 3,666
Consumer |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss | 1,748 | 1,434 | 1,315 | 1,288
Retained Earnings |  |  |  |
Item Effected |  |  |  |
Cumulative effect adjustment to retained earnings | $ 514,176 | 463,269 | 398,980 | 339,959
Cumulative Effect, Period of Adoption, Adjustment [Member] |  |  |  |
Item Effected |  |  |  |
Cumulative effect adjustment to retained earnings |  | (2,552) | (301) | 0
Financing Receivable, Allowance for Credit Loss |  | 2,584 |  |
Unfunded loan commitments |  | 777 |  |
Allowance for credit losses including off-balance sheet credit loss liability |  | 3,361 |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Commercial and agricultural |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | (655) |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Auto and light truck |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | (1,303) |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Medium and heavy duty truck |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 2,414 |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Aircraft |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 484 |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Construction equipment |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 372 |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Commercial real estate |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | (649) |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Residential real estate and home equity |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 1,688 |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Consumer |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 233 |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Earnings |  |  |  |
Item Effected |  |  |  |
Cumulative effect adjustment to retained earnings |  | (2,552) | (301) | 718
Net deferred tax amount of cumulative effect adjustment to retained earnings |  | 810 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] |  |  |  |
Item Effected |  |  |  |
Cumulative effect adjustment to retained earnings |  | 846,084 | 763,289 | 718,537
Financing Receivable, Allowance for Credit Loss |  | 113,838 |  |
Unfunded loan commitments |  | 3,949 |  |
Allowance for credit losses including off-balance sheet credit loss liability |  | 117,787 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commercial and agricultural |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 23,016 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Auto and light truck |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 13,097 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Medium and heavy duty truck |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 7,026 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Aircraft |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 31,542 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Construction equipment |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 14,492 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commercial real estate |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 17,701 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Residential real estate and home equity |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 5,297 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Consumer |  |  |  |
Item Effected |  |  |  |
Financing Receivable, Allowance for Credit Loss |  | 1,667 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Retained Earnings |  |  |  |
Item Effected |  |  |  |
Cumulative effect adjustment to retained earnings |  | $ 460,717 | $ 398,679 | $ 340,677

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