Changes in Estimates (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2020	Jun. 27, 2019	Jul. 02, 2020	Jun. 27, 2019
Change In Estimate [Line Items]
Changes in Contract Estimates, aggregate, Affecting earnings from Continuing Operations, per Share diluted	$ (1.45)	$ (0.08)	$ (1.55)	$ 0
Change In Accounting Estimate, aggregate	$ (231.8)	$ (10.9)	$ (247.3)	$ (0.1)
Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(37.7)	(13.2)	(33.5)	(7.1)
Forward Loss [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(194.1)	2.3	(213.8)	7.0
Fuselage Systems [Member] | Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(31.1)	(8.3)	(24.6)	(5.3)
Fuselage Systems [Member] | Forward Loss [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(155.1)	1.3	(168.3)	5.0
Wing Systems [Member] | Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(1.6)	1.7	(3.3)	1.7
Wing Systems [Member] | Forward Loss [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(22.8)	0.6	(26.2)	1.1
Propulsion Systems [Member] | Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(5.1)	(6.6)	(5.6)	(3.5)
Propulsion Systems [Member] | Forward Loss [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	$ (16.2)	$ 0.4	$ (19.3)	$ 0.9