Share-based Compensation (Tables)

9 Months Ended

Sep. 28, 2018

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Share-Based Compensation Expense Recorded in the Consolidated Statements of Operations

The table below summarizes share-based compensation expense recorded in the consolidated statements of operations (in thousands):

	ThreeMonths Ended				Nine Months Ended
	September 28,		September 29,		September 28,		September 29,
	2018		2017		2018		2017
Selling, general and administrative	$	1,523	$	1,336	$	5,021	$	3,911
Research and development and engineering		114		59		306		156
Cost of revenue		58		41		148		156
Total share-based compensation expense	$	1,695	$	1,436	$	5,475	$	4,223

Fair Value of TSR Performance-Based Restricted Stock Units Estimated Using Monte-Carol Valuation Model

The fair value of the TSR-PSUs at the date of grant was estimated using the Monte-Carlo valuation model with the following assumptions:

	Nine Months Ended September 28, 2018
Grant-date stock price	$	53.85
Expected volatility		30.35	%
Risk-free interest rate		2.37	%
Expected annual dividend yield		—
Fair value	$	70.49

2010 Incentive Award Plan

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Restricted Stock Issued and Outstanding

The table below summarizes activities relating to RSUs and DSUs issued and outstanding under the Company’s Amended and Restated 2010 Incentive Plan during the nine months ended September 28, 2018:

	Shares (In thousands)			Weighted Average Grant Date Fair Value
Unvested at December 31, 2017		614		$	18.35
Granted		123		$	54.36
Vested		(186	)	$	18.52
Forfeited		(27	)	$	24.53
Unvested at September 28, 2018		524		$	26.39
Expected to vest as of September 28, 2018		500

Performance-Based Awards Issued and Outstanding

The table below summarizes the activities relating to the performance-based awards issued and outstanding under the Company’s Amended and Restated 2010 Incentive Plan during the nine months ended September 28, 2018:

	Shares (In thousands)		Weighted Average Grant Date Fair Value
Unvested at December 31, 2017		89	$	24.00
Granted		48	$	62.17
Vested		—	$	—
Forfeited		—	$	—
Unvested at September 28, 2018		137	$	37.28