Employee Benefits and Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Share-Based Compensation Expense

The following table sets forth the total share-based compensation expense recognized in the Company’s Condensed Consolidated Statements of Operations for the three months ended March 31, 2020 and 2019:

	Three Months Ended March 31,
	2020		2019
	(In thousands)
Cost of product and service revenues	$	1,770	$	1,462
Research and development	1,768		1,702
Selling, general, and administrative	7,121		5,246
Total share-based compensation expense	$	10,659	$	8,410

Assumptions Used to Value Stock Options Granted

The following assumptions were used to value stock options and Employee Stock Purchase Plan (“ESPP”) shares granted pursuant to the Company’s equity incentive plans for the three months ended March 31, 2020 and 2019:

	Three Months Ended March 31,
	2020		2019
Stock options
Expected life, years	4.7		4.5
Expected volatility, %	33.6	%	33.1	%
Risk-free interest rate, %	1.4	%	2.6	%
Estimated forfeiture rate, %	5.7	%	7.2	%
Dividend yield, %	—	%	—	%

Assumptions Used to Value ESPP Shares Granted

	Three Months Ended March 31,
	2020		2019
Employee stock purchase plan shares
Expected life, years	0.5 - 2.0		0.5 - 2.0
Expected volatility, %	30.4% - 39.9%		28.2% - 38.4%
Risk-free interest rate, %	1.4% - 2.7%		1.3% - 2.7%
Dividend yield, %	—	%	—	%

Summary of Share Option Activity

The following table summarizes the share option activity under the Company’s equity incentive plans during the three months ended March 31, 2020:

	Number of Shares	Weighted-Average Exercise Price		Weighted-Average Remaining Years	Aggregate Intrinsic Value
	(In thousands, except per share data)
Outstanding at December 31, 2019	3,902	$	52.75	7.7	$	113,198
Granted	430	85.32
Exercised	(227)	36.20
Expired	(2)	51.50
Forfeited	(65)	64.06
Outstanding at March 31, 2020	4,038	$	56.96	7.8	$	57,180
Exercisable at March 31, 2020	1,586	$	39.38	6.3	$	42,826
Vested and expected to vest at March 31, 2020 and thereafter	3,846	$	56.18	7.7	$	56,526

Summary of Restricted Stock Unit Activity

Summaries of the restricted stock activity under the Company’s 2009 Equity Incentive Plan, as amended (the “2009 Plan”) are presented below for the three months ended March 31, 2020:

	Number of Shares	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Years	Aggregate Intrinsic Value
	(In thousands, except per share data)
Restricted stock units
Outstanding at December 31, 2019	544	$	66.65	1.6	$	44,492
Granted (Awarded)	62	85.05
Vested (Released)	(33)	54.41
Forfeited	(17)	66.06
Outstanding and unvested at March 31, 2020	556	$	69.44	1.6	$	36,482

Summary of Restricted Stock Awards Activity

	Number of Shares	Weighted-Average Grant Date Fair Value
	(In thousands, except per share data)
Restricted stock awards
Outstanding at December 31, 2019	17	$	81.92
Granted (Awarded)	—	—
Vested (Released)	—	—
Outstanding and unvested at March 31, 2020	17	$	81.92

Summary of Performance-Based Restricted Stock Activity

A summary of the performance-based restricted stock activity under the 2009 Plan is presented below for the three months ended March 31, 2020:

	Number of Shares	Weighted-Average Grant Date Fair Value Per Unit
	(In thousands, except per share data)
Outstanding at December 31, 2019	134	$	55.82
Granted	63	82.41
Vested	(15)	72.02
Forfeited	—	—
Outstanding and unvested at March 31, 2020	182	$	63.63

Ordinary Shares Reserved for Future Issuance Under Equity Incentive Plans

The Company had the following ordinary shares reserved for future issuance under its equity incentive plans as of March 31, 2020:

	Number of Shares
	(In thousands)
Share options outstanding	4,038
Non-vested restricted stock awards	755
Shares authorized for future issuance	2,252
ESPP shares available for future issuance	1,322
Total shares reserved for future issuance	8,367