STOCK PLANS (Tables)

6 Months Ended

Jun. 30, 2018

Stockholders' Equity Note [Abstract]

Schedule of recognized stock-based compensation in consolidated statements of operations

The Company recognized stock-based compensation expense in the periods presented as follows (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Cost of goods sold	$	1,046	$	1,395	$	2,252	$	2,770
Research and development	951		647		1,648		1,304
Selling, general and administrative	5,050		5,303		11,532		10,670
Total	$	7,047	$	7,345	$	15,432	$	14,744

Stock-based compensation from:
Stock options (employee awards)	$	4,827	$	5,741	$	11,182	$	11,658
Stock options (consultant awards)	202		29		241		83
Restricted stock units (employee awards)	1,819		1,389		3,609		2,611
Employee stock purchase plan	199		186		400		392
Total	$	7,047	$	7,345	$	15,432	$	14,744

Schedule of the Company's stock option activity and related information

The following tables contain information about the Company’s stock option and restricted stock unit, or RSU, activity for the six months ended June 30, 2018:



Stock Options	Number of Options		Weighted Average Exercise Price
Outstanding at December 31, 2017	4,951,493		$	43.51
Granted	1,683,007		38.33
Exercised	(103,263	)	14.45
Forfeited	(242,188	)	44.43
Expired	(253,483	)	64.19
Outstanding at June 30, 2018	6,035,566		41.65



Restricted Stock Units	Number of Units		Weighted Average Grant Date Fair Value
Unvested at December 31, 2017	499,546		$	47.32
Granted	327,779		38.33
Vested	(147,844	)	49.70
Forfeited	(42,722	)	45.86
Unvested at June 30, 2018	636,759		42.23