Share-Based Compensation (Tables)

3 Months Ended

Mar. 29, 2019

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
	March 29,		March 30,
	2019		2018
Selling, general and administrative	$	2,531	$	1,924
Research and development and engineering		111		84
Cost of revenue		85		36
Total share-based compensation expense	$	2,727	$	2,044

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:

	Three Months Ended March 29, 2019
Grant-date stock price	$	77.23
Expected volatility		32.54	%
Risk-free interest rate		2.46	%
Expected annual dividend yield		—
Fair value	$	108.58

2010 Incentive Award Plan

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

Restricted Stock Units and Deferred Stock Units 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 three months ended March 29, 2019:

	Shares (In thousands)			Weighted Average Grant Date Fair Value
Unvested at December 31, 2018		529		$	26.98
Granted		101		$	75.29
Vested		(141	)	$	28.33
Forfeited		(8	)	$	34.70
Unvested at March 29, 2019		481		$	36.61
Expected to vest as of March 29, 2019		454

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 three months ended March 29, 2019:

	Shares (In thousands)			Weighted Average Grant Date Fair Value
Unvested at December 31, 2018		137		$	37.28
Granted		44		$	92.93
Performance adjustment (1)		29		$	14.13
Vested		(59	)	$	14.13
Forfeited		—		$	—
Unvested at March 29, 2019		151		$	57.57

(1) Represents adjustment for performance-based awards granted on March 30, 2016. These units vested at 200% during the three months ended March 29, 2019 based on the achievement of cumulative Non-GAAP EPS during the performance period of fiscal years 2016 through 2018.