Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Intangible assets subject to amortization:
Gross Carrying Amount	$ 1,088.3	$ 1,087.8
Accumulated Amortization	(564.9)	(550.4)
Net Carrying Amount	523.4	537.4
Intangible assets not subject to amortization:
Intangible assets not subject to amortization	124.7	131.4
Gross intangible assets (excluding goodwill)	1,213.0	1,219.2
Accumulated Amortization	(564.9)	(550.4)
Total intangible assets, net carrying amount	648.1	668.8
Trade names
Intangible assets not subject to amortization:
Intangible assets not subject to amortization	116.0	122.7
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	514.9	518.1
Accumulated Amortization	(197.7)	(189.3)
Net Carrying Amount	317.2	328.8
Intangible assets not subject to amortization:
Accumulated Amortization	(197.7)	(189.3)
Technology and know-how
Intangible assets subject to amortization:
Gross Carrying Amount	265.9	270.7
Accumulated Amortization	(92.0)	(86.6)
Net Carrying Amount	173.9	184.1
Intangible assets not subject to amortization:
Accumulated Amortization	(92.0)	(86.6)
Trade names
Intangible assets subject to amortization:
Gross Carrying Amount	20.6	14.3
Accumulated Amortization	(8.6)	(9.6)
Net Carrying Amount	12.0	4.7
Intangible assets not subject to amortization:
Accumulated Amortization	(8.6)	(9.6)
Capitalized software
Intangible assets subject to amortization:
Gross Carrying Amount	283.7	280.0
Accumulated Amortization	(264.1)	(261.3)
Net Carrying Amount	19.6	18.7
Intangible assets not subject to amortization:
Accumulated Amortization	(264.1)	(261.3)
Other
Intangible assets subject to amortization:
Gross Carrying Amount	3.2	4.7
Accumulated Amortization	(2.5)	(3.6)
Net Carrying Amount	0.7	1.1
Intangible assets not subject to amortization:
Accumulated Amortization	$ (2.5)	$ (3.6)