Unpaid Claims - Paid Claims (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Claims Development [Line Items]
Cumulative net paid claims	$ 2,249,623	$ 1,443,830	$ 894,877
2019 and prior
Claims Development [Line Items]
Cumulative net paid claims	946,480	947,526	$ 894,877
2020
Claims Development [Line Items]
Cumulative net paid claims	611,027	$ 496,304
2021
Claims Development [Line Items]
Cumulative net paid claims	$ 692,116