Investment Securities - Revenue Bonds by Type (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
States and Political Subdivisions [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	$ 372,313	$ 397,234
Fair market value (available-for-sale securities and held-to-maturity securities)	372,371	381,007
Revenue Bonds [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	47,634	54,296
Fair market value (available-for-sale securities and held-to-maturity securities)	47,728	51,847
Revenue Bonds [Member] | Water [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	19,113	21,246
Fair market value (available-for-sale securities and held-to-maturity securities)	19,158	19,977
Revenue Bonds [Member] | Sewer [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	6,323	6,560
Fair market value (available-for-sale securities and held-to-maturity securities)	6,380	6,405
Revenue Bonds [Member] | Lease [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	6,070	7,035
Fair market value (available-for-sale securities and held-to-maturity securities)	6,312	7,250
Revenue Bonds [Member] | Sales Tax [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	4,349	4,123
Fair market value (available-for-sale securities and held-to-maturity securities)	4,010	3,934
Revenue Bonds [Member] | Other Revenue Source [Member]
Marketable Securities [Line Items]
Amortized cost (available-for-sale securities and held-to-maturity securities)	11,779	15,332
Fair market value (available-for-sale securities and held-to-maturity securities)	$ 11,868	$ 14,281