Acquisitions - Schedule of Allocation of Purchase Price for Acquisition (Detail) - USD ($) $ in Thousands	Sep. 23, 2016	Dec. 25, 2015	Jul. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 85,248	$ 85,248
Miconex [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	239
Accounts receivable	3,065
Inventories	6,198
Deferred tax assets	196
Prepaid expenses and other	214
Equipment and leasehold improvements	428
Goodwill	10,950
Purchased intangible assets	8,800
Total assets acquired	30,090
Bank borrowings	(3,027)
Accounts payable	(3,509)
Accrued compensation and related benefits	(432)
Other current liabilities	(576)
Deferred tax liability	(1,856)
Other liabilities	(24)
Total liabilities assumed	(9,424)
Purchase price allocated	20,666		$ 20,700
Marchi Thermal Systems Inc [Member]
Business Acquisition [Line Items]
Inventories	1,297
Equipment and leasehold improvements	767
Goodwill	18,380
Purchased intangible assets	23,370
Other non-current assets	26
Total assets acquired	43,840
Other liabilities	(100)
Total liabilities assumed	(100)
Purchase price allocated	$ 43,740