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Commitments - Summary of Financial Instrument Commitments (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Fixed |  |
Financial instrument commitments |  |
Financial instrument commitments | $ 859 | $ 418
Fixed | Borrower |  |
Financial instrument commitments |  |
Financial instrument commitments | 859 | 418
Fixed | Borrower | Financial standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 327 | 177
Fixed | Borrower | Performance standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 532 | 241
Fixed | Unused lines of Credit |  |
Financial instrument commitments |  |
Loan commitments | 89,303 | 82,942
Variable |  |
Financial instrument commitments |  |
Financial instrument commitments | 14,003 | 11,860
Variable | Borrower |  |
Financial instrument commitments |  |
Financial instrument commitments | 13,936 | 11,718
Variable | Borrower | Financial standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 7,158 | 3,770
Variable | Borrower | Commercial standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 397 | 354
Variable | Borrower | Performance standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 6,381 | 7,594
Variable | Nonborrower | Performance standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 67 | 142
Variable | Unused lines of Credit |  |
Financial instrument commitments |  |
Loan commitments | 297,785 | 260,061
Total. |  |
Financial instrument commitments |  |
Financial instrument commitments | 14,862 | 12,278
Total. | Borrower |  |
Financial instrument commitments |  |
Financial instrument commitments | 14,795 | 12,136
Total. | Borrower | Financial standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 7,485 | 3,947
Total. | Borrower | Commercial standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 397 | 354
Total. | Borrower | Performance standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 6,913 | 7,835
Total. | Nonborrower | Performance standby |  |
Financial instrument commitments |  |
Financial instrument commitments | 67 | 142
Total. | Unused lines of Credit |  |
Financial instrument commitments |  |
Loan commitments | $ 387,088 | $ 343,003

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