Related Party Transactions - Narrative (Details) $ in Thousands													3 Months Ended			7 Months Ended		12 Months Ended
	Mar. 16, 2020	Aug. 12, 2019 USD ($)	Jul. 31, 2019 USD ($)	Jan. 11, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2018	Jul. 01, 2016	Jul. 01, 2013	Jan. 01, 2012 EUR (€)	Apr. 01, 2011 EUR (€)	Jun. 11, 2008	Jul. 01, 2007	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2019 USD ($)	Aug. 12, 2019	Jul. 31, 2019 USD ($)	Dec. 31, 2021 USD ($)	Jul. 01, 2018	Dec. 31, 2014
Related Party Transaction [Line Items]
Loan to related party													$ 167,975					$ 167,975
Interest income													6,750	$ 10,185
Notes Receivable, Related Party
Related Party Transaction [Line Items]
Interest income													$ 879	$ 860
Effective yield													2.10%	2.00%
Founding shareholders | AmTrust Financial Services, Inc.
Related Party Transaction [Line Items]
Controlling interest, ownership percentage													55.20%
AmTrust Financial Services, Inc. | London Interbank Offered Rate (LIBOR)
Related Party Transaction [Line Items]
Basis spread on variable rate																				2.00%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment
Related Party Transaction [Line Items]
Percent of premiums written, net of cost of unaffiliated inuring reinsurance from related party												40.00%
Percent of losses with respect to current lines of business, excluding those above covered business threshold to related party			40.00%					40.00%				40.00%
Commission rate, percent of ceded written premiums											34.375%	31.00%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Post-Termination Endorsement, Maximum Loss Corridor
Related Party Transaction [Line Items]
Related party transaction amount (returned)			$ 40,500
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Investments transferred out related to Partial Termination Amendment and Commutation
Related Party Transaction [Line Items]
Percent of ceding commission payable, period increase					5.00%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Returned Gross Unearned Premiums
Related Party Transaction [Line Items]
Related party transaction amount (returned)															$ 647,980
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Returned Unearned Premiums, Net
Related Party Transaction [Line Items]
Related party transaction amount (returned)															$ 436,760
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Commutation And Release Agreement Commutation Payment
Related Party Transaction [Line Items]
Related party transaction amount (returned)					$ 312,786
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Commutation And Release Agreement Net Ceded Reserves
Related Party Transaction [Line Items]
Related party transaction amount (returned)					$ 330,682
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Commutation And Release Agreement Commutation Payment Paid By Entity
Related Party Transaction [Line Items]
Related party transaction amount (returned)																	$ 17,896
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Commutation And Release Agreement, Commutation Payment, Premium Interest
Related Party Transaction [Line Items]
Related party interest expense		$ 6,335
Calculated interest rate with related party																3.30%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Investments transferred out for transactions under remaining AmTrust Quota Share business
Related Party Transaction [Line Items]
Related party transaction amount (returned)				$ 575,000									$ 575,000					$ 575,000
Calculated interest rate with related party													1.80%					1.80%
Accrued interest on collateral held by related party													$ 2,552					$ 2,609
Interest income from related party													2,552	$ 2,552
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Post-Termination Endorsement
Related Party Transaction [Line Items]
Related party transaction, percentage of required funding on obligations			105.00%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Post-Termination Endorsement, Minimum Excess Funding Requirement
Related Party Transaction [Line Items]
Related party transaction amount (returned)			$ 54,000
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Post-Termination Endorsement No. 2
Related Party Transaction [Line Items]
Related party transaction, percentage of required funding on obligations	110.00%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Minimum
Related Party Transaction [Line Items]
Commission rate, adjustment criteria, loss ratio floor								81.50%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Maximum
Related Party Transaction [Line Items]
Commission rate, adjustment criteria, loss ratio ceiling								95.00%
AmTrust Financial Services, Inc. | AmTrust Quota Share Reinsurance Segment | Maximum | Post-Termination Endorsement
Related Party Transaction [Line Items]
Related party transaction, percentage of required funding on obligations			110.00%
AmTrust Financial Services, Inc. | European Hospital Liability Quota Share Agreement
Related Party Transaction [Line Items]
Commission rate, percent of ceded written premiums										5.00%
Premiums and losses related to policies, percentage							32.50%			40.00%
Maximum limit of liability attaching (in EUR) | €									€ 10,000,000	€ 5,000,000
Percent basis currency equivalent of maximum limit of liability attaching										100.00%
Future premiums and losses related to policies, percentage							20.00%
AmTrust Financial Services, Inc. | European Hospital Liability Quota Share Agreement | Maximum | Post-Termination Endorsement No. 1
Related Party Transaction [Line Items]
Related party transaction, percentage of required funding on obligations	120.00%
Solvency ratio	100.00%
Collateral on exposure	100.00%
AmTrust Financial Services, Inc. | Reinsurer Trust Assets Collateral Agreement
Related Party Transaction [Line Items]
Collateral held by related party													138,810					246,874
Accrued interest on collateral held by related party													416					1,171
AmTrust Financial Services, Inc. | Reinsurance Brokerage Agreements
Related Party Transaction [Line Items]
Brokerage fee, percent of premium assumed												1.25%
AmTrust Financial Services, Inc. | Reinsurance Brokerage Agreements | Brokerage expense
Related Party Transaction [Line Items]
Expenses from related party transactions													(60)	(69)
Balance due to related party													1,021					1,147
AmTrust Financial Services, Inc. | Asset Management Agreement
Related Party Transaction [Line Items]
Quarterly brokerage fee, above portfolio threshold, percent of average holdings						0.02125%
Cancellation notice period						30 days
AmTrust Financial Services, Inc. | Asset Management Agreement | Investment Management Fee
Related Party Transaction [Line Items]
Expenses from related party transactions													(126)	(272)
AEL | AmTrust Quota Share Reinsurance Segment
Related Party Transaction [Line Items]
Percentage ceded																			20.00%
AEL | AmTrust European Hospital Liability Quota Share Agreement
Related Party Transaction [Line Items]
Collateral held by related party													234,633					244,488
Accrued interest on collateral held by related party													1,538					1,273
AmTrust International Underwriters DAC (AIU) | AmTrust European Hospital Liability Quota Share Agreement | Collateral Provided For Share Under Quota Share Agreement
Related Party Transaction [Line Items]
Related party transaction amount (returned)													$ 25,755					26,460
Calculated interest rate with related party													0.50%
Interest income from related party													$ 26	$ 37
AmTrust International Underwriters DAC (AIU) | AmTrust European Hospital Liability Quota Share Agreement | Accrued Interest On Collateral Provided For Share Under Quota Share Agreement
Related Party Transaction [Line Items]
Related party transaction amount (returned)													163					141
Affiliated Entity | Limited Partnership Agreement | 683 Capital Management, LLC
Related Party Transaction [Line Items]
Related party transaction amount (returned)													$ 32,861					$ 32,929
Maiden Holdings, Ltd. | Leah Karfunkel
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage													7.80%
Maiden Holdings, Ltd. | Barry Zyskind
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage													7.30%
Maiden Holdings, Ltd. | George Karfunkel, less than 5% ownership
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage													5.00%
Maiden Holdings, Ltd. | Affiliated Entity | 683 Capital Partners, LP
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage													6.70%