Acquisitions And Goodwill (Schedule Of Revenue And Net Income (Loss) For Vocollect, Including Amortization Of Intangibles And Other Purchase Accounting Charges Resulting From Acquisition) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2011		Oct. 02, 2011	Jul. 03, 2011	Apr. 03, 2011	Dec. 31, 2010	Sep. 26, 2010	Jun. 27, 2010	Mar. 28, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Revenue	$ 236,800	[1]	$ 211,800	$ 221,100	$ 178,500	$ 200,000	$ 168,700	$ 161,200	$ 149,200	$ 848,181	$ 679,111	$ 658,205
Vocollect [Member]
Segment Reporting Information [Line Items]
Revenue										106,214
Net income										$ 412

[1] Includes a $20.9 million tax expense in 2011. For the year ended December 31, 2011, a valuation allowance was required against a portion of our U.S. deferred tax assets and we recorded an increase of $20.9 million in our valuation allowance during the year ended December 31, 2011. This increase was reflected as an expense in the fourth quarter of 2011. There were no similar charges in any of the other years presented.