Bank Line of Credit	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Bank Line of Credit	Bank Line of CreditWe have access to a $100 million bank revolving line of credit with a $25 million letter of credit sublimit that expires on October 29, 2026. As of December 31, 2023, a total of $99.1 million remains available under the facility due to $0.9 million outstanding letters of credit, which reduce the availability for letters of credit to $24.1 million. We had no borrowings outstanding on our line of credit as of December 31, 2023. Investments with a fair value of $117.6 million were pledged as collateral on the line of credit at December 31, 2023. These investments have no trading restrictions and are reported as available-for-sale securities and cash and cash equivalents on our Statement of Financial Position as of December 31, 2023.  The bank requires compliance with certain covenants, which include leverage ratios and debt restrictions.  We are in compliance with all covenants at December 31, 2023.