Goodwill and Other Purchased Intangible Assets - Changes in Carrying Value of Goodwill by Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended		3 Months Ended
	Mar. 28, 2015		Dec. 27, 2014		Dec. 27, 2014
Segment Reporting Information [Line Items]
Goodwill	$ 63,132	[1]	$ 71,313
Impact of currency exchange	(2,806)		(5,126)
Impairment of goodwill			(3,055)
Goodwill	60,326		63,132	[1]	63,132	[1]
Semiconductor Equipment [Member]
Segment Reporting Information [Line Items]
Goodwill	63,132		67,983
Impact of currency exchange	(2,806)		(4,851)
Goodwill	60,326		63,132		63,132
Microwave Communications Equipment [Member]
Segment Reporting Information [Line Items]
Goodwill			3,330
Impact of currency exchange			(275)
Impairment of goodwill			$ (3,055)		$ (3,100)

[1] Derived from December 27, 2014 audited financial statements