Claims, Lawsuits and Other Contingencies (Details) case in Thousands, £ in Millions, $ in Millions	1 Months Ended				48 Months Ended
	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