Investments in debt and equity securities - Schedule of Debt Securities According to Contractual Terms (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Amortized costs
In one year or less	$ 74,177
After one year through five years	280,783
After five years through ten years	186,074
After ten years	13,741
Amortized costs	554,775	$ 558,544
Fair values
In one year or less	74,065
After one year through five years	279,233
After five years through ten years	185,330
After ten years	12,533
Fair values	$ 551,161	$ 558,488