Retirement Benefit Plans - Change in Benefit Obligation (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in benefit obligation:
Actuarial gains	$ (12.3)	$ 11.6	$ (8.0)	$ 3.9	$ 3.5
Pension Plan
Change in benefit obligation:
Actuarial gains						$ 16.0	$ 4.4	$ 16.2
U.S. Plans | Pension Plan
Change in benefit obligation:
Benefit obligation at beginning of year						566.3	663.1
Service cost						6.9	9.5	10.7
Interest cost						17.7	17.6	21.0
Plan amendments						0.0	0.0
Actuarial gains						(116.4)	(4.4)
International plan exchange rate change						0.0	0.0
Benefits paid						(139.2)	(119.5)
Acquisitions						0.0	0.0
Benefit obligation at end of year	335.3		566.3			335.3	566.3	663.1
International Plans | Pension Plan
Change in benefit obligation:
Benefit obligation at beginning of year						343.1	379.7
Service cost						1.6	2.0	1.8
Interest cost						5.7	4.4	5.5
Plan amendments						0.0	0.5
Actuarial gains						(88.2)	(19.6)
International plan exchange rate change						(32.6)	(8.7)
Benefits paid						(14.7)	(15.2)
Acquisitions						3.2	0.0
Benefit obligation at end of year	$ 218.1		$ 343.1			$ 218.1	$ 343.1	$ 379.7