Changes in Estimates (Details) - USD ($) $ / shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2018	Jun. 29, 2017	Jun. 28, 2018	Jun. 29, 2017
Change In Estimate [Line Items]
Current Period Forward Loss Recorded			$ (1.2)
Cumulative Catch Up Adjustment			$ (0.4)	$ 29.1
Changes in Contract Estimates, aggregate, Affecting earnings from Continuing Operations, per Share diluted	$ 180	$ (1,750)	$ (10)	$ (1,730)
Change In Accounting Estimate, aggregate	$ 24.9	$ (329.2)	$ (1.6)	$ (328.5)
Reduction In Previously Reported Forward-Loss				(357.6)
Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	7.5	24.3
Change in Estimate on Loss Program [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting		(353.5)
Forward Loss [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	17.4
Fuselage Systems [Member]
Change In Estimate [Line Items]
Current Period Forward Loss Recorded			(1.5)
Cumulative Catch Up Adjustment			(2.5)	3.3
Reduction In Previously Reported Forward-Loss				(237.6)
Fuselage Systems [Member] | Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	5.7	0.7
Fuselage Systems [Member] | Change in Estimate on Loss Program [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting		(231.7)
Fuselage Systems [Member] | Forward Loss [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	10.1
Wing Systems [Member]
Change In Estimate [Line Items]
Cumulative Catch Up Adjustment			0.7	22.0
Reduction In Previously Reported Forward-Loss			(0.5)	(72.0)
Wing Systems [Member] | Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	(1.6)	17.5
Wing Systems [Member] | Change in Estimate on Loss Program [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	3.0	(73.8)
Propulsion Systems [Member]
Change In Estimate [Line Items]
Current Period Forward Loss Recorded				(48.0)
Cumulative Catch Up Adjustment			1.4	$ 3.8
Reduction In Previously Reported Forward-Loss			$ 0.8
Change in Accounting Estimate - Contract Accounting	4.3
Propulsion Systems [Member] | Cumulative catch-up adjustment [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting	$ 3.4	6.1
Propulsion Systems [Member] | Change in Estimate on Loss Program [Member]
Change In Estimate [Line Items]
Change in Accounting Estimate - Contract Accounting		$ (48.0)