Reinsurance - Summary of Reinsurance Claims Incurred and Ceded (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Reinsurance Disclosures [Abstract] | ||||
| Claims incurred, gross | $ 590,951 | $ 452,261 | ||
| Claims incurred, ceded | (483) | (1,616) | ||
| Net claims incurred and claims adjustment expense | $ 214,432 | $ 146,328 | $ 590,468 | $ 450,645 |