Related Party Transactions - Schedule of AmTrust Quota Share Arrangement (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Related Party Transaction [Line Items] | ||||
| Gross premiums written | $ 2,117 | $ 521,526 | $ (559,022) | $ 1,144,854 |
| Net premiums earned | 133,986 | 504,388 | 317,088 | 1,021,201 |
| Net loss and loss adjustment expenses (loss and LAE) | (121,561) | (370,001) | (274,250) | (723,207) |
| Commission expenses | (49,656) | (162,780) | (119,273) | (329,408) |
| Quota Share Reinsurance Agreements | AmTrust Financial Services, Inc. | ||||
| Related Party Transaction [Line Items] | ||||
| Gross premiums written | (9,127) | 491,485 | ||
| Net premiums earned | 111,833 | 477,202 | 269,963 | 981,001 |
| Net loss and loss adjustment expenses (loss and LAE) | (109,091) | (351,954) | (247,035) | (696,483) |
| Commission expenses | $ (40,111) | $ (148,500) | $ (98,490) | $ (304,350) |