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Claims, Lawsuits and Other Contingencies (Details) case in Thousands, £ in Millions, $ in Millions | 1 Months Ended | 48 Months Ended |  |  |
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Jun. 30, 2022 USD ($) | Jun. 30, 2022 GBP (£) | May 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2018 case | Dec. 31, 2022 USD ($) | Dec. 31, 2022 GBP (£) | Dec. 31, 2020 USD ($) | Dec. 31, 2020 GBP (£) | Feb. 28, 2019 USD ($) | Feb. 28, 2019 GBP (£)
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Loss contingency, estimate of possible loss |  |  |  |  |  |  |  | $ 210 | £ 155.0 |  |
JLT Transaction |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Damages sought |  |  |  | $ 29 |  |  |  |  |  |  |
Individual cases analyzed | case |  |  |  |  | 14 |  |  |  |  |  |
Loss contingency accrual |  |  |  |  |  | $ 6 | £ 5.0 |  |  | $ 77 | £ 59.0
JLT Transaction | Columbia |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Damages sought |  |  | $ 2 |  |  |  |  |  |  |  |
Loss contingency, loss in period | $ 11 | £ 7.9 |  |  |  |  |  |  |  |  |

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