Employee Benefits and Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 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 and six months ended June 30, 2020 and 2019:

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
	(In thousands)
Cost of product and service revenues	$	2,130	$	1,416	$	3,900	$	2,878
Research and development	1,854		1,584		3,622		3,286
Selling, general, and administrative	7,367		5,260		14,488		10,506
Total share-based compensation expense	$	11,351	$	8,260	$	22,010	$	16,670

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 and six months ended June 30, 2020 and 2019:

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Stock options
Expected life, years	4.7		4.3		4.7		4.4
Expected volatility, %	42.2	%	33.2	%	37.9	%	33.2	%
Risk-free interest rate, %	0.5	%	2.1	%	0.9	%	2.3	%
Estimated forfeiture rate, %	5.7	%	7.2	%	5.7	%	7.2	%
Dividend yield, %	—	%	—	%	—	%	—	%

Assumptions Used to Value ESPP Shares Granted

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Employee stock purchase plan shares
Expected life, years	0.5 - 2.0		0.5 - 2.0		0.5 - 2.0		0.5 - 2.0
Expected volatility, %	30.4% - 39.9%		28.2% - 38.4%		30.4% - 39.9%		28.2% - 38.4%
Risk-free interest rate, %	1.4% - 2.7%		1.3% - 2.7%		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 six months ended June 30, 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	674	80.63
Exercised	(315)	37.28
Expired	(7)	56.83
Forfeited	(126)	62.61
Outstanding at June 30, 2020	4,128	$	58.17	7.4	$	65,499
Exercisable at June 30, 2020	1,699	$	41.50	6.0	$	50,644
Vested and expected to vest at June 30, 2020 and thereafter	3,945	$	57.46	7.3	$	64,859

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 six months ended June 30, 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)	89	81.25
Vested (Released)	(81)	56.57
Forfeited	(41)	63.67
Outstanding and unvested at June 30, 2020	511	$	71.03	1.5	$	36,062

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)	21	68.11
Vested (Released)	(17)	81.92
Outstanding and unvested at June 30, 2020	21	$	68.11

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 six months ended June 30, 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	(44)	54.25
Forfeited	(5)	81.72
Outstanding and unvested at June 30, 2020	148	$	66.69

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 June 30, 2020:

	Number of Shares
	(In thousands)
Share options outstanding	4,128
Non-vested restricted stock awards	680
Shares authorized for future issuance	2,029
ESPP shares available for future issuance	1,322
Total shares reserved for future issuance	8,159