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v3.20.1

Segment Reporting - Summary of the Schedule of the Company's gross written premiums based on the location of the insured risk (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | $ 3,442.4 | $ 3,446.9 | $ 3,360.9
Australia/Asia |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 215.9 | 175.9 | 167.3
Caribbean |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 9.3 | 7.7 | 17.6
Europe |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 82.8 | 92.6 | 94.5
United Kingdom |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 295.7 | 290.1 | 258.3
United States & Canada |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 2,003.9 | 1,875.9 | 1,729.3
Worldwide excluding United States |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 63.0 | 70.1 | 88.1
Worldwide including United States |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | 614.9 | 775.8 | 868.6
Others |  |  |
Segment Reporting Information [Line Items] |  |  |
Gross written premiums | $ 156.9 | $ 158.8 | $ 137.2

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- Definition Amount of direct and assumed premiums written. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 605 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547 + Details
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