Reconciliation of Statutory Canadian Tax rate to Effective Tax Rate (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Dec. 31, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Effective Tax Rate Reconciliation [Line Items]
Income Tax Provision (benefit)	$ (168)	$ 2,452	$ 6,310	$ 1,800	$ (6,013)	$ 2,013	$ 2,057	$ 937	$ 10,394	$ (1,006)	$ 6,200
Canada Revenue Agency
Schedule Of Effective Tax Rate Reconciliation [Line Items]
Statutory Canadian tax rate									27.00%	27.00%	26.00%
Expected income tax provision at Canadian statutory tax rate									$ 12,426	$ (4,837)	$ 4,206
International tax rate differences									304	(1,132)	156
State income taxes, net									453	(271)	148
Withholding and other taxes									680	421	321
Permanent differences									1,130	486	106
Section 199 deduction									(1,188)	(574)
Change in valuation allowance									(612)	4,809	(3,076)
Provision to return differences									(617)	962	(312)
Tax credits									(990)	(1,678)	(938)
Net operating loss expirations											4,538
Statutory tax rate change									95	(13)	354
Uncertain tax positions									121	134	259
IRS audit									(748)	241	680
JK Lasers divestiture									(1,432)
Goodwill impairment										330
Other									772	116	(242)
Income Tax Provision (benefit)									$ 10,394	$ (1,006)	$ 6,200
Effective tax rate									22.60%	5.60%	38.30%