Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Intangible assets subject to amortization:
Gross Carrying Amount	$ 1,394.3	$ 1,144.7
Accumulated Amortization	(590.3)	(540.9)
Net Carrying Amount	804.0	603.8
Intangible assets not subject to amortization:
Intangible assets not subject to amortization	131.3	161.5
Gross intangible assets (excluding goodwill)	1,525.6	1,306.2
Accumulated Amortization	(590.3)	(540.9)
Total intangible assets, net carrying amount	935.3	765.3
Trade names
Intangible assets not subject to amortization:
Intangible assets not subject to amortization	122.6	152.8
FAA air agency certificates
Intangible assets not subject to amortization:
Intangible assets not subject to amortization	8.7	8.7
Customer relationships
Intangible assets subject to amortization:
Gross Carrying Amount	698.7	561.5
Accumulated Amortization	(209.4)	(183.2)
Net Carrying Amount	489.3	378.3
Intangible assets not subject to amortization:
Accumulated Amortization	(209.4)	(183.2)
Technology and know-how
Intangible assets subject to amortization:
Gross Carrying Amount	318.2	273.1
Accumulated Amortization	(93.8)	(80.4)
Net Carrying Amount	224.4	192.7
Intangible assets not subject to amortization:
Accumulated Amortization	(93.8)	(80.4)
Trade names
Intangible assets subject to amortization:
Gross Carrying Amount	74.9	18.4
Accumulated Amortization	(10.4)	(8.7)
Net Carrying Amount	64.5	9.7
Intangible assets not subject to amortization:
Accumulated Amortization	(10.4)	(8.7)
Capitalized software
Intangible assets subject to amortization:
Gross Carrying Amount	294.7	288.4
Accumulated Amortization	(270.0)	(266.3)
Net Carrying Amount	24.7	22.1
Intangible assets not subject to amortization:
Accumulated Amortization	(270.0)	(266.3)
Other
Intangible assets subject to amortization:
Gross Carrying Amount	7.8	3.3
Accumulated Amortization	(6.7)	(2.3)
Net Carrying Amount	1.1	1.0
Intangible assets not subject to amortization:
Accumulated Amortization	$ (6.7)	$ (2.3)