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Loans And Allowance For Credit Losses (Narrative) (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items] |  |
Loans To Principal Holders (over 10% ownership in the Company's stock) | $ 0 |
Unfunded Loan Commitments | 13,000,000,000.0 |
Unused Approved Credit Card Lines of Credit | 5,000,000,000.0 |
Loans pledged at the Federal Home Loan Bank as collateral for borrowings and letters of credit obtained to secure public deposits | 3,900,000,000 |
Loans pledged at the Federal Reserve Bank as collateral for discount window borrowings | 1,500,000,000 |
Net Investment in Direct Financing and Sales Type Leases | 797,441,000 | $ 795,826,000
Deferred income on direct financing and sales-type leases | 66,300,000 | 71,800,000
Property Subject to or Available for Operating Lease, Net | $ 13,700,000 | 14,700,000
Period after which loans are deemed in default | 90 days |
Decrease in interest income resulting from modification to credit card loans | $ (965,000) |
Commitments to lend additional funds to customers with restructured loans | 10,700,000 | 4,700,000
Loans Held-for-sale, Fair Value Disclosure | 39,400,000 |
Unpaid Principal Balance on Personal Real Estate Loans Held for Sale | 38,000,000.0 |
Student Loans Held for Sale, Lower of Cost or Fair Value | 5,700,000 |
Personal Real Estate Loans HFS Past Due | 0 |
HFS Student Loans Past Due | 0 |
HFS Student Loans on Non-Accrual Status | 0 |
Personal Real Estate Loans HFS on Non-Accrual Status | 0 |
Foreclosed real estate | 93,000 | 365,000
Personal property acquired in repossession | 1,400,000 | $ 5,500,000
Business [Member] |  |
Loans and Leases Receivable Disclosure [Line Items] |  |
Financing Receivable, Nonaccrual, No Allowance | $ 9,400,000 |

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