Related-Party Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Related Party Transaction [Line Items]
Product sales to related parties	$ 307	$ 1,169	$ 2,898	$ 5,019
Service sales to related parties	351	245	903	613
Total sales to related parties	658	1,414	3,801	5,632
Purchases from related parties	436	66	1,804	289
Applied Materials [Member]
Related Party Transaction [Line Items]
Product sales to related parties	230	1,039	2,572	4,630
Service sales to related parties	256	220	611	550
Lattice Semiconductor [Member]
Related Party Transaction [Line Items]
Product sales to related parties	0	0	0	4
Service sales to related parties	3	3	9	9
Cascade Microtech [Member]
Related Party Transaction [Line Items]
Service sales to related parties	9	8	25	24
Oregon Health and Science University [Member]
Related Party Transaction [Line Items]
Product sales to related parties	77	130	326	385
Service sales to related parties	83	14	258	30
Purchases from related parties	41	39	119	214
TMC BV [Member]
Related Party Transaction [Line Items]
Purchases from related parties	$ 395	$ 27	$ 1,685	$ 75