CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 28, 2015
OPERATING ACTIVITIES:
Net income	$ 3,080	$ 664
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,086	2,493
Compensation for stock options and restricted stock units	1,482	1,198
Provision for bad debts	310	319
Loss on disposal of assets	64
Write-down of inventories	413	1,028
Deferred income tax expense	165	2,272
Income tax benefit from exercise of stock options	(65)	(292)
Decrease (increase) in:
Accounts receivable	11,109	18,405
Inventories	(1,585)	(14,221)
Prepaid expenses and other current assets	(717)	(1,562)
(Decrease) increase in:
Accounts payable and accrued liabilities	(5,305)	(9,550)
Income taxes payable	641	263
Customer deposits	(635)	(457)
Unearned service revenues	1,077	211
Net cash provided by operating activities	13,120	771
INVESTING ACTIVITIES:
Purchases of property and equipment	(2,057)	(2,436)
Payments for intangible assets	(322)	(133)
Purchase of businesses acquired		(12,011)
Net cash used in investing activities	(2,379)	(14,580)
FINANCING ACTIVITIES:
Payments on capital leases	(2)	(2)
Income tax benefit from exercise of stock options	65	292
Proceeds from issuance of stock, net	452	2,019
Net cash provided by financing activities	515	2,309
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	1,666	(1,723)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	12,922	(13,223)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	107,356	109,289
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 120,278	$ 96,066