Note 6 - Goodwill and Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Jan. 01, 2017	Mar. 27, 2016
Amortized intangible assets:
Carrying amount	$ 64,036	$ 64,036
Accumulated amortization	(54,434)	(52,301)
Net carrying amount	9,602	11,735
Technology-Based Intangible Assets [Member]
Amortized intangible assets:
Carrying amount	53,878	53,878
Accumulated amortization	(45,292)	(43,502)
Net carrying amount	$ 8,586	$ 10,376
Weighted average life (Year)	3 years 328 days	4 years 219 days
Customer Relationships [Member]
Amortized intangible assets:
Carrying amount	$ 5,225	$ 5,225
Accumulated amortization	(4,209)	(3,890)
Net carrying amount	$ 1,016	$ 1,335
Weighted average life (Year)	3 years	3 years 219 days
Distribution Rights [Member]
Amortized intangible assets:
Carrying amount	$ 1,264	$ 1,264
Accumulated amortization	(1,264)	(1,261)
Net carrying amount		3
Patents [Member]
Amortized intangible assets:
Carrying amount	3,459	3,459
Accumulated amortization	(3,459)	(3,459)
Net carrying amount
Trade Names [Member]
Amortized intangible assets:
Carrying amount	210	210
Accumulated amortization	(210)	(189)
Net carrying amount		$ 21