Quarterly Financial Data (Unaudited) - Quarterly Financial Data by Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jan. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Jan. 03, 2016	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Jan. 01, 2017	Jan. 03, 2016	Dec. 28, 2014
Segment Reporting Information [Line Items]
Net Sales	$ 552.9	$ 526.8	$ 539.7	$ 530.5	$ 600.0	$ 555.4	$ 577.7	$ 565.0	$ 2,149.9	$ 2,298.1	$ 2,394.0
Operating Income	70.5	68.8	53.6	60.9	76.0	69.5	68.9	67.3	253.8	281.7	294.5
Instrumentation
Segment Reporting Information [Line Items]
Net Sales									876.7	1,051.1	1,115.5
Operating Segments
Segment Reporting Information [Line Items]
Net Sales									2,149.9	2,298.1	2,394.0
Operating Income									253.8	281.7	294.5
Operating Segments | Instrumentation
Segment Reporting Information [Line Items]
Net Sales	224.6	208.3	220.1	223.7	266.3	243.2	271.3	270.3	876.7	1,051.1	1,115.5
Operating Income	30.2	28.1	20.1	31.4	44.6	38.6	45.7	42.1	109.8	171.0	181.6
Operating Segments | Digital Imaging
Segment Reporting Information [Line Items]
Net Sales	110.9	98.5	99.4	89.9	102.1	95.7	90.8	90.4	398.7	379.0	403.6
Operating Income	15.3	11.7	10.7	8.2	11.5	10.4	8.8	9.3	45.9	40.0	37.1
Operating Segments | Aerospace and Defense Electronics
Segment Reporting Information [Line Items]
Net Sales	151.8	153.5	158.0	152.6	153.9	151.3	147.0	141.2	615.9	593.4	603.0
Operating Income	28.5	31.5	28.0	24.1	21.3	23.5	20.6	19.4	112.1	84.8	88.3
Operating Segments | Engineered Systems
Segment Reporting Information [Line Items]
Net Sales	65.6	66.5	62.2	64.3	77.7	65.2	68.6	63.1	258.6	274.6	271.9
Operating Income	9.9	8.6	5.6	8.0	8.7	5.9	4.8	6.7	$ 32.1	$ 26.1	$ 31.4
Corporate
Segment Reporting Information [Line Items]
Operating Income	$ (13.4)	$ (11.1)	$ (10.8)	$ (10.8)	$ (10.1)	$ (8.9)	$ (11.0)	$ (10.2)