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Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk - Commitments (Details) - USD ($) $ in Thousands | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Company's contractual commitments due to letters of credit |  |
Total letters of credit | $ 16,418 | $ 16,801
Fixed [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 900 | 910
Variable [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 15,518 | 15,891
Commitments to Extend Credit to Borrowers [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 16,351 | 16,734
Commitments to Extend Credit to Borrowers [Member] | Fixed [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 900 | 910
Commitments to Extend Credit to Borrowers [Member] | Variable [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 15,451 | 15,824
Commitments to Extend Credit to Borrowers [Member] | Financial Standby Letter of Credit [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 9,710 | 9,951
Commitments to Extend Credit to Borrowers [Member] | Financial Standby Letter of Credit [Member] | Fixed [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 329 | 339
Commitments to Extend Credit to Borrowers [Member] | Financial Standby Letter of Credit [Member] | Variable [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 9,381 | 9,612
Commitments to Extend Credit to Borrowers [Member] | Performance Guarantee [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 6,641 | 6,783
Commitments to Extend Credit to Borrowers [Member] | Performance Guarantee [Member] | Fixed [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 571 | 571
Commitments to Extend Credit to Borrowers [Member] | Performance Guarantee [Member] | Variable [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 6,070 | 6,212
Commitments to Extend Credit Nonborrowers [Member] | Performance Guarantee [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 67 | 67
Commitments to Extend Credit Nonborrowers [Member] | Performance Guarantee [Member] | Variable [Member] |  |
Company's contractual commitments due to letters of credit |  |
Total letters of credit | 67 | 67
Letter of Credit [Member] | Unused lines of Credit [Member] |  |
Company's contractual commitments due to letters of credit |  |
Loan commitments | 439,482 | 431,468
Letter of Credit [Member] | Unused lines of Credit [Member] | Fixed [Member] |  |
Company's contractual commitments due to letters of credit |  |
Loan commitments | 112,537 | 111,348
Letter of Credit [Member] | Unused lines of Credit [Member] | Variable [Member] |  |
Company's contractual commitments due to letters of credit |  |
Loan commitments | $ 326,945 | $ 320,120

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