Retirement Benefit Plans - Employer Contributions to Defined Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employer Contributions [Abstract]
Employer Contributions to Defined Benefit Plans	$ 20.4	$ 17.9	$ 35.4
Accrued pension cost
Employer Contributions [Abstract]
Employer Contributions to Defined Benefit Plans	20.4	$ 17.9
2022 (estimated)	$ 9.5