Investments - Scheduled Contractual Maturities of Fixed-Maturity Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Cost or Amortized Cost	$ 167,143	$ 10,734
Due after one year through five years, Cost or Amortized Cost	232,353	19,222
Due after five years through ten years, Cost or Amortized Cost	3,854	11,503
Due after ten years, Cost or Amortized Cost	494	494
Fixed-maturity securities, Cost or Amortized Cost	403,844	41,953
Due in one year or less, Estimated Fair Value	167,002	10,826
Due after one year through five years, Estimated Fair Value	227,637	19,820
Due after five years through ten years, Estimated Fair Value	3,427	11,403
Due after ten years, Estimated Fair Value	505	534
Estimated Fair Value Total	$ 398,571	$ 42,583