Segment Information - Income (Loss) by Segment and Reconciliation to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 30, 2017	Jul. 31, 2016	Jul. 30, 2017	Jul. 31, 2016
Segment Reporting Information [Line Items]
Operating income (loss)	$ 18,892	$ 16,427	$ 37,148	$ 29,695
Items to reconcile segment operating income to consolidated income before taxes
Intangible amortization	6,675	6,328	12,961	12,731
Share-based compensation	15,525	6,097	28,810	11,804
Changes in the fair value of contingent earn-out obligations	0	(129)	0	(162)
Restructuring charges	0	0	429	0
Non-operating expense, net	204	136	836	181
Income before taxes	16,659	14,254	32,237	25,547
Corporate, Non-Segment [Member]
Items to reconcile segment operating income to consolidated income before taxes
Intangible amortization	6,675	6,328	12,961	12,731
Share-based compensation	15,525	6,097	28,810	11,804
Changes in the fair value of contingent earn-out obligations	0	(129)	0	(162)
Restructuring charges	0	0	429	0
Other non-segment related expenses	1,764	1,551	2,540	2,793
Amortization of fair value adjustments related to acquired property, plant and equipment	0	308	190	617
Interest expense, net	2,029	2,037	4,075	3,967
Non-operating expense, net	204	136	836	181
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	42,856	30,582	82,078	57,478
Semiconductor Products Group [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	42,856	32,497	82,078	59,954
All others [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	$ 0	$ (1,915)	$ 0	$ (2,476)