Restructuring and Related Charges (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			3 Months Ended			3 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended		3 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Mar. 31, 2012	Apr. 02, 2011	Jul. 02, 2011	Dec. 31, 2011 CommTest Solutions Business Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 CommTest Solutions Business Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 CommTest Germantown Restructuring Plan Communications Test and Measurement	Oct. 01, 2011 CCOP Fiscal Q1 2012 Plan Communications and Commercial Optical Products employee	Mar. 31, 2012 CCOP Fiscal Q1 2012 Plan Communications and Commercial Optical Products employee	Mar. 31, 2012 CommTest Market Rebalancing Restructuring Plan	Mar. 31, 2012 CommTest Market Rebalancing Restructuring Plan	Mar. 31, 2012 Other plans	Mar. 31, 2012 Other plans	Mar. 31, 2012 Maryland and Indiana in the United States CommTest US Manufacturing Outsourcing Restructuring Plan Communications Test and Measurement	Jun. 27, 2009 Germany CommTest Germany Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 Germany CommTest Germany Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 Workforce reduction CommTest Manufacturing Support Consolidation Plan employee	Mar. 31, 2012 Workforce reduction CommTest Manufacturing Support Consolidation Plan	Mar. 31, 2012 Workforce reduction CommTest Solutions Business Restructuring Plan	Mar. 31, 2012 Workforce reduction CommTest Solutions Business Restructuring Plan	Mar. 31, 2012 Workforce reduction CCOP Fiscal Q1 2012 Plan	Mar. 31, 2012 Workforce reduction CommTest Sales Rebalancing Restructuring Plan	Mar. 31, 2012 Workforce reduction CommTest Sales Rebalancing Restructuring Plan	Mar. 31, 2012 Workforce reduction CommTest Market Rebalancing Restructuring Plan	Apr. 02, 2011 Workforce reduction CommTest Market Rebalancing Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 Workforce reduction CommTest Market Rebalancing Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 Workforce reduction CommTest Germany Restructuring Plan	Mar. 31, 2012 Workforce reduction CommTest Germany Restructuring Plan	Mar. 31, 2012 Workforce reduction Other plans	Mar. 31, 2012 Facilities and Equipment CommTest Market Rebalancing Restructuring Plan	Mar. 31, 2012 Facilities and Equipment CommTest Market Rebalancing Restructuring Plan	Apr. 02, 2011 Facilities and Equipment CommTest Market Rebalancing Restructuring Plan Communications Test and Measurement facility	Mar. 31, 2012 Facilities and Equipment Other plans	Mar. 31, 2012 Lease Costs CommTest Germantown Restructuring Plan	Mar. 31, 2012 Lease Costs CommTest Market Rebalancing Restructuring Plan	Mar. 31, 2012 Lease Costs CommTest US Manufacturing Outsourcing Restructuring Plan	Mar. 31, 2012 Lease Costs CommTest US Manufacturing Outsourcing Restructuring Plan	Mar. 31, 2012 Lease Costs Other plans	Mar. 31, 2012 Lease Costs Other plans	Mar. 31, 2012 Sales organization and product portfolios reorganization CommTest Sales Rebalancing Restructuring Plan Communications Test and Measurement employee	Jul. 02, 2011 Sales organization and product portfolios reorganization CommTest Sales Rebalancing Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 Sales organization and product portfolios reorganization CommTest Sales Rebalancing Restructuring Plan Communications Test and Measurement employee	Mar. 31, 2012 Ottawa Lease Exit Costs
Restructuring and Related Charges
Restructuring and related charges	$ 2.0	$ 7.6	$ 7.5	$ 10.4
Number of employees expected to be reduced						59			40							77		89								128																89
Number of positions eliminated as of the balance sheet date							31			40							60										127														87		87
Restructuring and related charges																																									(0.1)		(0.7)
Contractual obligations under the operating lease, net of sublease income, fair value	4.9		4.9		5.9			0.6							1.1												1.1
Summary of various restructuring plans
Accrual balance at the beginning of the period			15.4									3.6		2.2										4.5	3.6				3.3	1.0								1.8		1.2				5.9
Restructuring and related charges	2.0		7.5								0.1	1.5	(0.5)	0.1				2.7	2.7	(0.1)	1.7	1.1	(0.1)	(0.7)	(0.3)			0.1	0.6		0.1	0.7		0.8	0.6	1.1	(0.2)	(0.1)	(0.5)	(0.7)
Cash Settlements			(12.9)									(3.9)		(1.8)							(1.0)	(1.1)		(3.6)	(3.1)				(0.7)	(0.8)		(0.7)		(0.8)		(0.1)		(0.8)		(0.2)				(0.9)
Non-cash settlements and other adjustments			(0.3)									0.1		(0.1)															(0.5)	(0.1)						0.1		0.2						(0.1)
Accrual balance at the end of the period	$ 9.7		$ 9.7								$ 1.3	$ 1.3	$ 0.4	$ 0.4				$ 2.7	$ 2.7	$ 0.7	$ 0.7		$ 0.2	$ 0.2	$ 0.2			$ 2.7	$ 2.7	$ 0.1					$ 0.6	$ 1.1	$ 1.1	$ 1.1	$ 0.3	$ 0.3				$ 4.9
Number of facilities exited																																	3