Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2013	Dec. 29, 2012
Summary of Finite-lived intangible assets
Adjusted cost	$ 31,927	$ 31,497
Accumulated amortization	(24,063)	(20,517)
Net carrying amount	7,864	10,980
Developed technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	18,095	17,700
Accumulated amortization	(11,032)	(8,277)
Net carrying amount	7,063	9,423
Customer relationships [Member]
Summary of Finite-lived intangible assets
Adjusted cost	9,573	9,538
Accumulated amortization	(9,263)	(8,643)
Net carrying amount	310	895
Brand names [Member]
Summary of Finite-lived intangible assets
Adjusted cost	1,927	1,927
Accumulated amortization	(1,700)	(1,599)
Net carrying amount	227	328
Patented technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	2,252	2,252
Accumulated amortization	(1,988)	(1,922)
Net carrying amount	264	330
Trademark [Member]
Summary of Finite-lived intangible assets
Adjusted cost	80	80
Accumulated amortization	(80)	(76)
Net carrying amount	$ 0	$ 4