Revenue Disaggregation and Outstanding Performance Obligations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 26, 2019	Jun. 27, 2019	Mar. 28, 2019	Dec. 31, 2018	Sep. 27, 2018	Jun. 28, 2018	Mar. 29, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 1,959.3	$ 1,919.9	$ 2,016.1	$ 1,967.8	$ 1,835.3	$ 1,813.7	$ 1,836.9	$ 1,736.1	$ 7,863.1	$ 7,222.0	$ 6,983.0
Expected to be satisfied in year 2019 [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	3,777.2								3,777.2
Expected to be satisfied in year 2020 [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	4,645.0								4,645.0
Expected to be satisfied in year 2021 [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	4,686.1								4,686.1
Expected to be satisfied in year 2022 and thereafter [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2,829.2								2,829.2
Transferred over Time [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									5,963.5	5,628.5
Transferred at Point in Time [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									1,899.6	1,593.5
Location United States [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									6,566.3	5,967.1
Location United Kingdom [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									771.9	763.3
Other Countries [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									524.9	491.6	$ 519.2
Disaggregation of revenue, total international locations [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									1,296.8	1,254.9
Boeing - all programs [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									6,237.2	5,677.7
Airbus [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									1,250.6	1,180.8
Other Customer [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues									$ 375.3	$ 363.5