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Reserve for Losses and Loss Adjustment Expenses - Prior year development (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2022 | Mar. 31, 2021
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | $ 141,812 | $ 41,672
Operating segments | Insurance |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | $ 7,300 | $ 4,100
Percentage of prior year development | 0.70% | 0.50%
Operating segments | Insurance | Short tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | $ 19,000 | $ 25,000
Operating segments | Insurance | Short tailed lines | Property excluding marine |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | 14,600
Operating segments | Insurance | Short tailed lines | Travel and accident |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | 2,500
Operating segments | Insurance | Short tailed lines | Lenders products |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | 18,600 | 8,000
Operating segments | Insurance | Medium tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | (20,900)
Operating segments | Insurance | Medium tailed lines | Programs |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | 5,000 | (10,800)
Operating segments | Insurance | Medium tailed lines | Professional liability |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | (7,200) | (6,000)
Operating segments | Insurance | Medium tailed lines | Contract binding |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | (6,000) |
Operating segments | Insurance | Medium tailed lines | Surety |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | (5,000)
Operating segments | Insurance | Long tailed lines | Casualty |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | (5,800) |
Operating segments | Insurance | Medium tailed and long tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | (11,700) |
Operating segments | Reinsurance |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | $ 32,500 | $ 26,800
Percentage of prior year development | 4.00% | 4.20%
Operating segments | Reinsurance | Short tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | $ 17,500
Operating segments | Reinsurance | Short tailed lines | Property catastrophe and property other than property catastrophe |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | $ 19,200 | 23,300
Operating segments | Reinsurance | Short tailed lines | Property catastrophe |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | (22,500)
Operating segments | Reinsurance | Short tailed lines | Other specialty lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | 16,600
Operating segments | Reinsurance | Medium tailed lines | Marine and aviation |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | 10,700 |
Operating segments | Reinsurance | Long tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | (2,900) |
Operating segments | Reinsurance | Short tailed and medium tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | 35,400 |
Operating segments | Reinsurance | Medium tailed and long tailed lines |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | 9,300
Operating segments | Mortgage |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) | $ 102,100 | $ 10,900
Percentage of prior year development | 35.30% | 3.20%
Operating segments | Other |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |
Prior year development favorable (unfavorable) |  | $ (100)

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- Definition Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437 + Details
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