Segment Information - Income (Loss) by Segment and Reconciliation to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
May. 01, 2016	Apr. 26, 2015
Segment Reporting Information [Line Items]
Operating income	$ 13,267	$ 4,884
Items to reconcile segment operating income to consolidated income before taxes
Stock-based compensation expense	5,707	5,946
Changes in the fair value of contingent earn-out obligations	(33)	162
Environmental reserve	0	(2,335)
Interest expense, net	1,930	1,834
Non-operating (income) expense, net	45	493
Income before taxes	11,292	2,557
Corporate, Non-Segment [Member]
Items to reconcile segment operating income to consolidated income before taxes
Intangible amortization and impairments	6,403	6,163
Stock-based compensation expense	5,707	5,946
Changes in the fair value of contingent earn-out obligations	(33)	162
Environmental reserve	0	2,335
Other non-segment related expenses	1,242	3,038
Amortization of fair value adjustments related to acquired PP&E	308	548
Interest expense, net	1,930	1,834
Non-operating (income) expense, net	45	493
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	26,894	23,076
Semiconductor Products Group [Member]
Segment Reporting Information [Line Items]
Operating income	27,454	25,327
All others [Member]
Segment Reporting Information [Line Items]
Operating income	$ (560)	$ (2,251)

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Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

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The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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