Business Segments (Business Segments) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 28, 2014		Sep. 28, 2014		Jun. 29, 2014		Mar. 30, 2014		Dec. 29, 2013		Sep. 29, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 28, 2014		Dec. 29, 2013		Dec. 30, 2012
Sales
Sales	$ 622.3	[1]	$ 601.1	[1]	$ 597.1	[1]	$ 573.5	[1]	$ 596.6	[2]	$ 571.6	[2]	$ 601.0	[2]	$ 569.4	[2]	$ 2,394.0		$ 2,338.6		$ 2,127.3
Income before taxes
Total segment operating profit																	294.5		240.3		243.1
Corporate expense																	(43.9)		(37.6)		(36.7)
Interest and debt expense, net																	(19.0)		(20.4)		(17.8)
Other income, net																	6.6		4.1		2.9
Income before taxes																	282.1		224.0		228.2
Depreciation and amortization
Depreciation and amortization																	94.3		91.1		78.3
Capital expenditures
Capital expenditures																	43.5		72.6		65.3
Identifiable assets
Identifiable assets	2,862.2								2,751.1								2,862.2		2,751.1		2,406.4
Prepaid pension assets	86.3								222.0								86.3		222.0		0
Operating Segments [Member]
Income before taxes
Total segment operating profit																	338.4		277.9		279.8
Instrumentation
Sales
Sales																	1,115.5		1,022.8		804.7
Income before taxes
Total segment operating profit																	181.6		162.0		146.0
Depreciation and amortization
Depreciation and amortization																	41.1		38.2		26.1
Capital expenditures
Capital expenditures																	17.0		22.0		14.4
Identifiable assets
Identifiable assets	1,415.4								1,204.5								1,415.4		1,204.5		1,022.5
Digital Imaging
Sales
Sales																	403.6		414.8		415.9
Income before taxes
Total segment operating profit																	37.1		28.2		24.8
Depreciation and amortization
Depreciation and amortization																	29.6		30.3		30.5
Capital expenditures
Capital expenditures																	10.3		20.2		23.5
Identifiable assets
Identifiable assets	708.4								745.1								708.4		745.1		778.1
Aerospace and Defense Electronics
Sales
Sales																	603.0		625.1		605.3
Income before taxes
Total segment operating profit																	88.3		65.7		80.5
Depreciation and amortization
Depreciation and amortization																	15.9		16.5		17.1
Capital expenditures
Capital expenditures																	8.8		15.3		12.6
Identifiable assets
Identifiable assets	462.5								436.9								462.5		436.9		457.6
Engineered Systems
Sales
Sales																	271.9		275.9		301.4
Income before taxes
Total segment operating profit																	31.4		22.0		28.5
Depreciation and amortization
Depreciation and amortization																	3.7		4.2		4.4
Capital expenditures
Capital expenditures																	4.3		3.6		4.2
Identifiable assets
Identifiable assets	84.9								92.3								84.9		92.3		102.3
Corporate
Depreciation and amortization
Depreciation and amortization																	4.0		1.9		0.2
Capital expenditures
Capital expenditures																	3.1		11.5		10.6
Identifiable assets
Identifiable assets	$ 191.0	[3]							$ 272.3	[3]							$ 191.0	[3]	$ 272.3	[3]	$ 45.9	[3]

[1] Fiscal year 2014 was a P364D-week year, each quarter contained P91D weeks.

[2] Fiscal year 2013 was a P364D-week year, each quarter contained P91D weeks.

[3] 2013 includes the $86.3 million and $222.0 million prepaid pension asset, respectively. The Company had no prepaid pension assets in 2012.