Investments in Available-for-Sale Securities - Schedule of investments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	$ 30,493	$ 37,014
Available-for-sale, Gross Unrealized Gains	5	21
Available-for-sale, Gross Unrealized Losses	(51)	(42)
Available-for-sale, Fair Value	30,447	36,993
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	26,506	28,325
Available-for-sale, Gross Unrealized Gains	1	1
Available-for-sale, Gross Unrealized Losses	(38)	(25)
Available-for-sale, Fair Value	26,469	28,301
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	3,987	8,689
Available-for-sale, Gross Unrealized Gains	4	20
Available-for-sale, Gross Unrealized Losses	(13)	(17)
Available-for-sale, Fair Value	$ 3,978	$ 8,692