Segment Information - Income (Loss) by Segment and Reconciliation to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 30, 2016	Oct. 25, 2015	Oct. 30, 2016	Oct. 25, 2015
Segment Reporting Information [Line Items]
Operating income (loss)	$ 39,099	$ 18,898	$ 68,794	$ 26,850
Items to reconcile segment operating income to consolidated income before taxes
Share-based compensation	9,395	5,117	21,198	13,397
Changes in the fair value of contingent earn-out obligations	0	(14,186)	(162)	(13,618)
Restructuring charge	0	962	0	4,526
Interest expense, net	1,890	1,964	5,857	5,698
Non-operating expense, net	690	777	871	1,152
Income before taxes	36,519	16,157	62,066	20,000
Corporate, Non-Segment [Member]
Items to reconcile segment operating income to consolidated income before taxes
Intangible amortization and impairments	6,286	6,308	19,017	18,648
Share-based compensation	9,395	5,117	21,199	13,397
Changes in the fair value of contingent earn-out obligations	0	(14,186)	(162)	(13,618)
Restructuring charge	0	962	0	4,526
Environmental reserve	0	0	0	2,855
Other non-segment related (income) expenses	3,139	2,792	5,938	10,073
Amortization of fair value adjustments related to acquired PP&E	308	310	925	948
Interest expense, net	1,890	1,964	5,857	5,698
Non-operating expense, net	690	777	871	1,152
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	58,227	20,201	115,711	63,679
Semiconductor Products Group [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	33,013	22,019	92,973	70,054
All others [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	$ 25,214	$ (1,818)	$ 22,738	$ (6,375)