Organization and Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2017

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Customers as Percentage of Total Sales

The Company’s most significant customers (having accounted for 10% or more of sales) and their related sales as a percentage of total sales were as follows:

	Three Months Ended						Six Months Ended
	June 30,			June 24,			June 30,			June 24,
	2017			2016			2017			2016
Lam Research Corporation		57.1	%		55.4	%		57.9	%		56.0	%
Applied Materials, Inc.		25.7			27.0			26.3			25.2
Total		82.8	%		82.4	%		84.2	%		81.2	%

Assets or Liabilities Measured at Fair Value

The following table summarizes, for assets or liabilities measured at fair value, the respective fair value and the classification by level of input within the fair value hierarchy (in thousands):

			Fair Value Measurement at
			Reporting Date Using
Description	June 30, 2017		QuotedPrices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Other assets:
Interest rate swap	$	33	$	—	$	33	$	—
Forward contracts	$	841	$	—	$	841	$	—
Other liabilities:
Interest rate swap	$	5	$	—	$	5	$	—
Contingent earn-out liability	$	897	$	—	$	—	$	897

			Fair Value Measurement at
			Reporting Date Using
Description	December 30, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Other assets:
Interest rate swap	$	15	$	—	$	15	$	—
Other liabilities:
Interest rate swap	$	6	$	—	$	6	$	—
Contingent earn-out liability	$	278	$	—	$	—	$	278

Schedule of Option Activity

Stock option activity for the six months ended June 30, 2017:

	Shares			Weighted Average Exercise Price		Weighted Remaining Contractual Life (years)		Aggregate IntrinsicValue (in thousands)
Outstanding at December 30, 2016		136,459		$	13.15		0.57	$	135
Granted		—
Exercised		(112,362	)		13.97
Cancelled		(13,825	)		14.56
Outstanding at June 30, 2017		10,272		$	2.32		1.60	$	169
Options exercisable at June 30, 2017		10,272		$	2.32		1.60	$	169

Summary of Restricted Stock Unit and Restricted Stock Award Activity

The following table summarizes the Company’s RSU and RSA activity for the six months ended June 30, 2017:

	Shares			Aggregate FairValue (in thousands)
Unvested restricted stock units and restricted stock awards    at December 30, 2016		1,757,507		$	16,466
Granted		346,750
Vested		(610,092	)
Forfeited		(41,327	)
Unvested restricted stock units and restricted stock awards    at June 30, 2017		1,452,838		$	26,256
Vested and expected to vest restricted stock units and    restricted stock awards at June 30, 2017		1,222,726		$	21,942

Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations

The following table shows the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations (in thousands):

	Three Months Ended						Six Months Ended
	June 30,			June 24,			June 30,			June 24,
	2017			2016			2017			2016
Cost of sales (1)	$	258		$	190		$	601		$	466
Research and development		47			67			100			128
Sales and marketing		97			100			221			177
General and administrative		978			761			1,840			1,412
		1,380			1,118			2,762			2,183
Income tax benefit		(184	)		(840	)		(498	)		—
Stock-based compensation expense, net of tax	$	1,196		$	278		$	2,264		$	2,183

(1) Stock-based compensation expenses capitalized in inventory for the three and six months ended June 30, 2017 and June 24, 2016 were not significant.