Related-Party Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2014	Mar. 31, 2013
Related Party Transaction [Line Items]
Product sales to related parties	$ 1,089	$ 3,621
Service sales to related parties	261	153
Total sales to related parties	1,350	3,774
Purchases from related parties	447	25
Applied Materials [Member]
Related Party Transaction [Line Items]
Product sales to related parties	959	3,492
Service sales to related parties	168	133
Oregon Health and Science University [Member]
Related Party Transaction [Line Items]
Product sales to related parties	130	129
Service sales to related parties	82	9
Purchases from related parties	39	0
Lattice Semiconductor [Member]
Related Party Transaction [Line Items]
Service sales to related parties	3	3
Cascade Microtech [Member]
Related Party Transaction [Line Items]
Service sales to related parties	8	8
TMC BV [Member]
Related Party Transaction [Line Items]
Purchases from related parties	$ 408	$ 25