Goodwill - Schedule of Changes in Carrying Amounts of Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 603.7	$ 602.7
Accumulated impairment losses	(59.5)	(59.5)
Total	544.2	543.2
Acquisition	0.9
Foreign currency translation	0.1
Commercial
Goodwill [Line Items]
Goodwill	387.9	387.0
Total	387.9	387.0
Acquisition	0.9
Aviation
Goodwill [Line Items]
Goodwill	215.8	215.7
Accumulated impairment losses	(59.5)	(59.5)
Total	156.3	$ 156.2
Foreign currency translation	$ 0.1