Investments (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($) item security	Dec. 31, 2024 USD ($) security	Sep. 30, 2024 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Fair value	$ 469,285	$ 508,604
Number of investments in a single issuer exceeds 10% of shareholders' equity | item	0
Percent of shareholders equity benchmark for investments in a single issuer	10.00%
Number of debt securities | security	484	538
Fair Value	$ 410,804	$ 476,913
Unrealized Losses	30,932	45,710	$ 14,800
Public Funds And Trust Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value	$ 386,900	$ 207,200