STOCK PLANS (Tables)

3 Months Ended

Mar. 31, 2020

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 March 31,
	2020		2019
Cost of goods sold	$	1,219	$	1,091
Research and development	1,186		1,218
Selling, general and administrative	6,442		5,125
Total	$	8,847	$	7,434
Stock-based compensation from:
Stock options	$	6,225	$	5,121
Restricted stock units	2,402		2,107
Employee stock purchase plan	220		206
Total	$	8,847	$	7,434

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 three months ended March 31, 2020:

Stock Options	Number of Options	Weighted Average Exercise Price (Per Share)
Outstanding at December 31, 2019	6,706,378	$	42.80
Granted	188,450	43.53
Exercised	(207,548)	16.64
Forfeited	(91,069)	41.66
Expired	(14,057)	63.34
Outstanding at March 31, 2020	6,582,154	43.62

Restricted Stock Units	Number of Units	Weighted Average Grant Date Fair Value (Per Share)
Unvested at December 31, 2019	631,141	$	41.87
Granted	350	43.27
Vested	(849)	48.16
Forfeited	(15,567)	41.89
Unvested at March 31, 2020	615,075	41.86