Investments - Amortized Cost and Estimated Fair Value, Net of Credit Loss Allowance, of Available-For-Sale Securities by Contractual Maturity (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Amortized cost
Due in one year or less	$ 46,749
Due after one year through five years	428,383
Due after five years through ten years	189,051
Due after ten years	304,678
Amortized cost	968,861
Estimated fair value
Due in one year or less	45,733
Due after one year through five years	408,641
Due after five years through ten years	181,638
Due after ten years	279,654
Estimated fair value	$ 915,666