Reinsurance - Summary of Premium Earned 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] | ||||
| Premiums earned, gross | $ 666,297 | $ 457,758 | ||
| Premiums earned, ceded | (599) | (832) | ||
| Net premiums earned | $ 199,376 | $ 163,710 | $ 665,698 | $ 456,926 |