Segment Information - Net Sales by the Originating Geographic Area and Estimated End Market (Detail) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 02, 2016 USD ($)	Jul. 03, 2016 USD ($)	Apr. 03, 2016 USD ($)	Jan. 03, 2016 USD ($)	Sep. 27, 2015 USD ($)	Jun. 28, 2015 USD ($)	Mar. 29, 2015 USD ($)	Dec. 28, 2014 USD ($)	Oct. 02, 2016 USD ($) segment	Sep. 27, 2015 USD ($)	Sep. 28, 2014 USD ($)
Segment Reporting Disclosure [Line Items]
Number of Reportable Segments | segment									1
Net Sales	$ 450.1	$ 431.4	$ 444.3	$ 329.2	$ 328.8	$ 317.1	$ 296.2	$ 303.5	$ 1,655.0	$ 1,245.6	$ 1,138.3
Aerospace
Segment Reporting Disclosure [Line Items]
Net Sales									495.4	527.2	472.3
Communication
Segment Reporting Disclosure [Line Items]
Net Sales									$ 618.0	439.8	401.0
Defense And Security
Segment Reporting Disclosure [Line Items]
Concentration of credit risk in major customer									30.00%
Net Sales									$ 276.9	11.9	6.6
Industrial
Segment Reporting Disclosure [Line Items]
Net Sales									264.7	266.7	258.4
United States
Segment Reporting Disclosure [Line Items]
Net Sales									628.2	610.0	604.4
Europe
Segment Reporting Disclosure [Line Items]
Net Sales									$ 222.8	$ 189.8	$ 163.7
Asia
Segment Reporting Disclosure [Line Items]
Concentration of credit risk in major customer								12.00%	18.00%	12.00%	0.00%
Net Sales									$ 749.2	$ 399.7	$ 338.4
Other Geographical [Member]
Segment Reporting Disclosure [Line Items]
Net Sales									$ 54.8	$ 46.1	$ 31.8