Income Taxes - Schedule of Pre-Tax Income (Loss) and Effective Income Tax Rates (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ (52.8)	$ 28.2	$ (44.9)	$ 138.1
Effective Tax Rate	7.60%	20.60%	(47.00%)	11.70%
Bermuda
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ (11.3)	$ 7.2	$ (60.3)	$ 14.5
Effective Tax Rate	0.00%	0.00%	0.00%	0.00%
United States
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ (3.2)	$ 21.4	$ 81.6	$ 126.7
Effective Tax Rate	46.30%	26.80%	20.70%	20.70%
United Kingdom
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ (37.6)	$ (6.1)	$ (23.9)	$ (14.9)
Effective Tax Rate	6.80%	(1.00%)	(16.20%)	68.40%
Brazil
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ 0.0	$ 5.9	$ (0.1)	$ 9.8
Effective Tax Rate	0.00%	0.00%	(422.40%)	0.00%
United Arab Emirates
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ 0.5	$ 0.9	$ 1.3	$ 1.2
Effective Tax Rate	0.00%	0.00%	0.00%	0.00%
Ireland
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ (1.3)	$ 0.0	$ (39.3)	$ (0.1)
Effective Tax Rate	0.00%	0.00%	0.00%	0.00%
Italy
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ 0.1	$ 0.2	$ (0.1)	$ 1.4
Effective Tax Rate	(1.70%)	0.00%	(46.40%)	0.00%
Malta
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ 0.0	$ (1.3)	$ (4.1)	$ (0.4)
Effective Tax Rate	0.00%	0.00%	0.00%	0.00%
Switzerland
Income Tax Examination [Line Items]
Pre-Tax Income (Loss)	$ 0.0	$ 0.0	$ 0.0	$ (0.1)
Effective Tax Rate	0.00%	0.00%	0.00%	0.00%