Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2017

Equity [Abstract]

Summary of Restricted Stock Unit Activity

The following table summarizes RSU activity for the nine months ended September 30, 2017 (number of units and aggregate intrinsic value in thousands):

	Number of Units		Weighted Average Grant-Date Fair Value		Aggregate Intrinsic Value
Units outstanding, beginning of year	1,330		$	20.40
Granted	1,176		24.90
Released	(403	)	18.70
Forfeited	(87	)	23.34
Units outstanding, end of period	2,016		23.22		$	45,703

Summary of the Stock Option Activity

The following table summarizes stock option activity for the nine months ended September 30, 2017 (number of units and aggregate intrinsic value in thousands):

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value
Options outstanding, beginning of year	1,008		$	5.40
Granted	—		—
Exercised	(171	)	7.35
Expired / terminated	(6	)	10.43
Options outstanding, end of period	831		4.98		1.66	$	14,706
Options exercisable, end of period	802		4.99		1.68	14,180
Options expected to vest, end of period	25		4.75		1.23	448

Stock-Based Compensation

The following table summarizes the composition of stock stock-based compensation for the three months ended September 30, 2017 and 2016 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Cost of products sold and services delivered	$	134	$	77	$	368	$	247
Sales, general and administrative expenses	2,099		1,348		6,282		4,197
Research and development expenses	1,767		791		4,773		2,298
Total stock-based compensation	$	4,000	$	2,216	$	11,423	$	6,742