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Short-Term Borrowings - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022
Federal Funds Purchased |  |
Short-term borrowings |  |
Unsecured maximum borrowing capacity | $ 87.0 | $ 87.0
Outstanding credit facility | 0.0 | 0.0
FHLB short-term advances |  |
Short-term borrowings |  |
Outstanding credit facility | 706.6 | $ 531.6
Unsecured Line Of Credit With Bank of North Dakota |  |
Short-term borrowings |  |
Unused line of credit | $ 20.0 |

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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
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