Segment Information - Net Sales by the Originating Geographic Area and Estimated End Market (Detail) $ in Millions	3 Months Ended								9 Months Ended	12 Months Ended
	Oct. 01, 2017 USD ($)	Jul. 02, 2017 USD ($)	Apr. 02, 2017 USD ($)	Jan. 01, 2017 USD ($)	Oct. 02, 2016 USD ($)	Jul. 03, 2016 USD ($)	Apr. 03, 2016 USD ($)	Jan. 03, 2016 USD ($)	Jul. 02, 2017 segment	Oct. 01, 2017 USD ($) segment	Oct. 02, 2016 USD ($)	Sep. 27, 2015 USD ($)
Segment Reporting Disclosure [Line Items]
Number of Reportable Segments | segment									1	1
Net Sales	$ 475.3	$ 458.1	$ 442.9	$ 435.5	$ 450.1	$ 431.4	$ 444.3	$ 329.2		$ 1,811.8	$ 1,655.0	$ 1,245.6
Aerospace
Segment Reporting Disclosure [Line Items]
Net Sales										473.4	495.4	527.2
Communication
Segment Reporting Disclosure [Line Items]
Net Sales										$ 641.0	618.0	439.8
Defense And Security
Segment Reporting Disclosure [Line Items]
Concentration of credit risk in major customer										26.00%
Net Sales										$ 421.4	276.9	11.9
Industrial
Segment Reporting Disclosure [Line Items]
Net Sales										276.0	264.7	266.7
United States
Segment Reporting Disclosure [Line Items]
Net Sales										597.8	628.2	610.0
Europe
Segment Reporting Disclosure [Line Items]
Net Sales										$ 230.7	$ 222.8	$ 189.8
Asia
Segment Reporting Disclosure [Line Items]
Concentration of credit risk in major customer										19.00%	18.00%	12.00%
Net Sales										$ 922.0	$ 749.2	$ 399.7
Other Geographical [Member]
Segment Reporting Disclosure [Line Items]
Net Sales										$ 61.3	$ 54.8	$ 46.1