Segment Information (PY Table) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 6,316.6	$ 6,047.9	$ 5,029.6
Cost of Goods and Services Sold	7,689.0	5,841.7	4,981.0
Excess Capacity Costs- B737MAX and A320 Production Schedules	(196.5)	(184.1)	(157.3)
Gross Operating Income	(1,372.4)	206.2	48.6
Restructuring Charges	(0.7)	(7.2)	(0.2)
Other Expenses	0.0	(5.9)	0.0
Cost of Sales	(7,492.5)	(5,657.6)	(4,814.9)
Segment Reporting, Unallocated Selling, General and Administrative Expense	(365.5)
Selling, General and Administrative Expense	(365.5)	(281.9)	(279.2)
Segment Information Unallocated Research And Development	(47.5)
Research and Development Expense	(47.5)	(45.4)	(50.4)
Operating loss	(1,786.1)	(134.2)	(281.2)
Consolidated Business Segments Operating Income	(1,373.1)	193.1	48.4
Interest and Debt Expense	(353.5)	(318.7)	(244.1)
Other Operating Income (Expense), Net	(2.0)	(140.4)	(14.1)
Loss before income taxes and equity in net income (loss) of affiliates	(2,141.6)	(593.3)	(539.4)
Commercial [Member]
Segment Reporting Information [Line Items]
Revenues	4,927.4	4,885.0	4,068.4
Excess Capacity Costs- B737MAX and A320 Production Schedules	(186.5)	(177.3)	(149.5)
Segment Gross Income	(1,522.4)	80.4	(82.7)
Restructuring Charges	0.7	6.3	0.2
Other Expenses		(8.1)
Cost of Sales	(6,263.3)	(4,627.3)	(3,993.0)
Operating loss	(1,523.1)	66.0	(82.9)
Business Segment Operating Income	(1,523.1)	66.0	(82.9)
Loss before income taxes and equity in net income (loss) of affiliates	(1,523.1)	66.0	(82.9)
Defense & Space [Member]
Segment Reporting Information [Line Items]
Revenues	975.2	789.0	649.8
Excess Capacity Costs- B737MAX and A320 Production Schedules	(10.0)	(6.8)	(7.8)
Segment Gross Income	94.7	45.8	72.8
Restructuring Charges	0.0	0.9	0.0
Other Expenses		(0.2)
Cost of Sales	(870.5)	(736.4)	(571.5)
Operating loss	94.7	44.7	72.8
Business Segment Operating Income	94.7	44.7	72.8
Loss before income taxes and equity in net income (loss) of affiliates	94.7	44.7	72.8
Aftermarket [Member]
Segment Reporting Information [Line Items]
Revenues	414.0	373.9	311.4
Excess Capacity Costs- B737MAX and A320 Production Schedules	0.0	0.0	0.0
Segment Gross Income	55.3	80.0	58.5
Restructuring Charges	0.0	0.0	0.0
Other Expenses		2.4
Cost of Sales	(358.7)	(293.9)	(250.4)
Operating loss	55.3	82.4	58.5
Business Segment Operating Income	55.3	82.4	58.5
Loss before income taxes and equity in net income (loss) of affiliates	55.3	82.4	58.5
unallocated
Segment Reporting Information [Line Items]
Segment Reporting, Unallocated Selling, General and Administrative Expense		(281.9)	(279.2)
Segment Information Unallocated Research And Development		(45.4)	(50.4)
Operating loss	(413.0)	(327.3)	(329.6)
Interest and Debt Expense	(353.5)	(318.7)	(244.1)
Other Operating Income (Expense), Net	(2.0)	(140.4)	(14.1)
Loss before income taxes and equity in net income (loss) of affiliates	$ (768.5)	$ (786.4)	$ (587.8)