Inventory (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Summary Of Inventories [Abstract]
Raw materials	$ 414.4	$ 332.7
Work-in-process(1)	1,283.7	1,044.9
Finished goods	48.4	69.4
Product inventory	1,746.5	1,447.0
Capitalized pre-production	20.8	23.7
Total inventory, net	1,767.3	1,470.7
Inventory [Line Items]
Excess Capacity Costs- B737MAX and A320 Production Schedules	184.1	157.3
COVID-19 U.S. employee retention credit and U.K. government subsidies		$ 9.6
Other Nonrecurring Expense	$ 8.3