Retirement Benefits - Savings Plan (Details) - USD ($) $ in Millions		12 Months Ended
	Apr. 01, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Matching defined contribution expense		$ 19.1	$ 19.1	$ 11.9
Defined contribution plan maximum annual contribution per employee percent	2.00%		2.00%
U.S. 401(K)
Defined Contribution Plan Disclosure [Line Items]
Matching defined contribution expense		7.6	$ 6.5	2.0
Other plans
Defined Contribution Plan Disclosure [Line Items]
Matching defined contribution expense		$ 11.5	$ 12.6	$ 9.9