Stockholders' Equity (Tables)

12 Months Ended

Dec. 28, 2018

Schedule of Share-based Compensation, Fair Value of Stock-Based Compensation Granted

The following table represents the fair value of stock-based compensation granted during the year ended 2018 (in thousands):

	Fair Value
Stock options	$	9,702
Restricted stock units		849
Restricted stock		335
Total stock-based compensation expense	$	10,886

Schedule of Compensation Cost

The cost that has been charged against income for stock-based compensation is set forth below (in thousands):

	Years Ended
	2018		2017		2016
Employee stock option	$	4,013	$	1,731	$	5,485
Restricted stock		274		186		298
Restricted stock units		2,120		1,226		2,717
Nonemployee stock options		355		18		58
Total stock-based compensation expense	$	6,762	$	3,161	$	8,558

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The Company recorded stock-based compensation expense in the following categories (in thousands):

	Years Ended
	2018		2017		2016
Cost of sales	$	15	$	8	$	612
General and administrative		2,635		1,487		3,809
Marketing and selling		1,805		805		1,961
Research and development		2,307		861		2,176
Total stock-based compensation expense, net		6,762		3,161		8,558
Amounts capitalized as part of inventory		637		372		269
Total stock-based compensation expense, gross	$	7,399	$	3,533	$	8,827

Schedule of Unrecognized Compensation Cost, Non-Vested Stock-Based Compensation Arrangements

As of December 28, 2018, total unrecognized compensation cost related to non-vested stock-based compensation arrangements granted under the Plan were as follows (in thousands):

	2018
Stock options	$	9,767
Restricted stock and restricted stock units		2,007
Total unrecognized stock-based compensation cost	$	11,774

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The risk-free rate is based on the U.S. Treasury yield curve corresponding to the expected term at the time of the grant.

	Years Ended
	2018			2017			2016
Expected dividend yield		0	%		0	%		0	%
Expected volatility		53	%		57	%		57	%
Risk-free interest rate		2.71	%		1.96	%		1.34	%
Expected term (in years)		5.72			5.67			5.57

Schedule of Share-based Compensation, Stock Options, Activity

A summary of option activity under the Plan for the year ended December 28, 2018 is presented below:

	Shares (in 000’s)			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in 000’s)
Outstanding at December 29, 2017		3,725		$	8.78
Granted		826			23.19
Exercised		(596	)		8.72
Forfeited or expired		(35	)		11.27
Outstanding at December 28, 2018		3,920		$	11.80		6.80	$	76,615
Exercisable at December 28, 2018		2,660		$	8.53		5.79	$	60,455

Share-based Compensation, Performance Shares Award Unvested Activity

A summary of unvested options activity under the Plan for the year ended December 28, 2018 was as follows:

	Shares (in 000’s)			Weighted- Average Grant-Date Fair Value
Unvested at December 29, 2017		1,148		$	4.96
Granted		826			11.95
Forfeited or expired		(35	)		5.73
Vested		(679	)		4.90
Unvested at December 28, 2018		1,260		$	9.67

Summary of Weighted Average Grant Date Fair Value of Options Granted and Total intrinsic Value of options Exercised

The weighted average grant date fair value of options granted and the total intrinsic value of options exercised were as follows:

	Years Ended
	2018		2017		2016
Weighted-average grant-date fair value	$	11.95	$	5.42	$	3.77
Intrinsic value of options (in thousands)	$	13,699	$	3,065	$	1,737

Restricted Stock

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

A summary of restricted stock activity under the Plan for the year ended December 28, 2018 was as follows:

	Shares (in 000’s)			Weighted- Average Grant- Date Fair Value
Outstanding at December 29, 2017		21		$	9.60
Granted		11			29.43
Vested		(21	)		9.70
Outstanding at December 28, 2018		11		$	29.80

Restricted Stock Units (RSUs)

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

A summary of restricted stock units’ activity under the Plan for the year ended December 28, 2018 was as follows:

	Units (in 000’s)			Weighted- Average Grant- Date Fair Value
Outstanding at December 29, 2017		488		$	9.45
Granted		49			17.22
Vested		(206	)		9.65
Forfeited or expired		(9	)		11.05
Outstanding at December 28, 2018		322		$	10.46