Business Segments (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 30, 2012		Sep. 30, 2012		Jul. 01, 2012		Apr. 01, 2012		Jan. 01, 2012		Oct. 02, 2011		Jul. 03, 2011		Apr. 03, 2011		Dec. 30, 2012 segment	Jan. 01, 2012	Jan. 02, 2011
Revenue from External Customer [Line Items]
Number of reportable segments																	4
Summary of the segments sales by product line
Sales	$ 567.4	[1]	$ 547.4	[1]	$ 518.5	[1]	$ 494.0	[1]	$ 474.5	[2]	$ 496.4	[2]	$ 502.9	[2]	$ 468.1	[2]	$ 2,127.3	$ 1,941.9	$ 1,644.2
Sales to international customers																	831.7	689.9	470.8
Aerospace and Defense Electronics [Member]
Revenue from External Customer [Line Items]
Number of product lines	1																1
Summary of the segments sales by product line
Sales																	660.6	670.8	614.7
Instrumentation [Member]
Revenue from External Customer [Line Items]
Number of product lines	3																3
Summary of the segments sales by product line
Sales																	749.4	616.6	573.2
Engineered Systems [Member]
Revenue from External Customer [Line Items]
Number of product lines	3																3
Summary of the segments sales by product line
Sales																	301.4	304.6	333.8
Digital Imaging [Member]
Revenue from External Customer [Line Items]
Number of product lines	1																1
Summary of the segments sales by product line
Sales																	415.9	349.9	122.5
Environmental Instrumentation [Member] | Instrumentation [Member]
Summary of the segments sales by product line
Sales																	250.2	243.8	219.8
Marine Instrumentation [Member] | Instrumentation [Member]
Summary of the segments sales by product line
Sales																	418.4	372.8	353.4
Test and Measurement Instrumentation [Member] | Instrumentation [Member]
Summary of the segments sales by product line
Sales																	80.8	0	0
Engineered Products and Services [Member] | Engineered Systems [Member]
Summary of the segments sales by product line
Sales																	241.3	246.2	279.9
Turbine Engines [Member] | Engineered Systems [Member]
Summary of the segments sales by product line
Sales																	24.6	23.8	17.0
Energy Systems [Member] | Engineered Systems [Member]
Summary of the segments sales by product line
Sales																	35.5	34.6	36.9
United States Department of Defense [Member]
Summary of the segments sales by product line
Sales																	542.6	560.6	555.0
Domestic Operations [Member]
Summary of the segments sales by product line
Sales to international customers																	$ 492.2	$ 424.8	$ 397.7

[1] Fiscal year 2012 was a 52-week year, each quarter contained 13 weeks.

[2] Fiscal year 2011 was a 52-week year, each quarter contained 13 weeks.