Employee Benefits and Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-Based Compensation Expense Recognized in Consolidate Statements of Income

The following table sets forth the total share-based compensation expense recognized in the Company's Condensed Consolidated Statements of Operations:

	Three months ended				Six months ended
	June 30, 2017		June 30, 2016		June 30, 2017		June 30, 2016
	(In thousands)
Cost of product and service revenues	$	845	$	644	$	1,827	$	1,193
Research and development	810		801		1,707		1,442
Selling, general and administrative	3,890		4,050		7,522		6,751
Total share-based compensation expense	$	5,545	$	5,495	$	11,056	$	9,386

Estimate of Fair Value of Share-Based Awards, Share Options

The following weighted average assumptions are used to value stock options and Employee Stock Purchase Plan ("ESPP") shares issued pursuant to the Company's equity incentive plans for the three and six months ended June 30, 2017 and 2016:

	Three months ended				Six months ended
	June 30, 2017		June 30, 2016		June 30, 2017		June 30, 2016
Stock Option Plans
Expected life, years	4.67		4.92		4.67		4.92
Expected volatility, %	28.3	%	31.5	%	29.7	%	32.0	%
Risk free interest rate, %	1.78	%	1.41	%	1.84	%	1.40	%
Estimated forfeiture rate %	7.7	%	8.6	%	7.7	%	8.6	%
Dividend yield, %	—	%	—	%	—	%	—	%

Estimate of Fair Value of Share-Based Awards, Employee Stock Purchase Plan

	Three months ended				Six months ended
	June 30, 2017		June 30, 2016		June 30, 2017		June 30, 2016
Employee Stock Purchase Plan
Expected life, years	0.5-2.0		0.5-2.0		0.5-2.0		0.5-2.0
Expected volatility, %	25.8-32.8%		25.8-34.8%		25.8-32.8%		25.8-34.8%
Risk free interest rate, %	0.52-1.31%		0.26-0.79%		0.52-1.31%		0.26-0.79%
Dividend yield, %	—	%	—	%	—	%	—	%

Stock Option Activity under the Equity Incentive Plans

The following table summarizes the share option activity under the Company’s equity incentive plans during the six months ended June 30, 2017:

	Number of Shares		Weighted-Average Exercise Price		Weighted-Average Remaining Years	Aggregate Intrinsic Value
	(In thousands, except per share data)
Stock Options
Outstanding at December 31, 2016	3,214		$	26.06	7.3	$	26,331
Granted	409		37.21
Exercised	(423	)	21.69
Expired	(3	)	24.36
Forfeited	(56	)	32.14
Outstanding at June 30, 2017	3,141		$	27.99	7.4	$	47,445
Exercisable at June 30, 2017	1,382		$	21.61	5.6	$	29,696
Vested and expected to vest at June 30, 2017 and thereafter	2,985		$	27.66	7.3	$	46,078

Restricted Stock Units Activity under the Stock Option Activity under the Equity Incentive Plans

The following table summarizes the restricted stock activity under the Company’s equity incentive plans during the six months ended June 30, 2017:

	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 ("RSUs")
Outstanding at December 31, 2016	505		$	31.42	1.6	$	17,135
Granted	86		37.21
Vested	(96	)	28.88
Forfeited	(11	)	32.17
Outstanding and unvested at June 30, 2017	484		$	32.93	1.4	$	20,901

Restricted Stock Units Award under the Stock Option Activity under the Equity Incentive Plans

	Number of Shares		Weighted-Average Grant Date Fair Value
	(In thousands, except per share data)
Restricted Stock Awards ("RSAs")
Outstanding at December 31, 2016	30		$	31.57
Granted	24		41.10
Vested	(30	)	31.58
Forfeited	—		—
Outstanding and unvested at June 30, 2017	24		$	41.03

Performance Shares Restricted Stock Activity under the Stock Option Activity under the Equity Incentive Plans

The following table summarizes the performance-based restricted stock activity under the Company’s equity incentive plans during the six months ended June 30, 2017:

	Number of Shares		Weighted-Average Grant Date Fair Value Per Unit
	(In thousands, except per share data)
Performance-based Restricted Stock Units ("PSUs")
Outstanding at December 31, 2016	184		$	24.89
Granted	126		32.37
Vested	(69	)	24.43
Forfeited	—		—
Outstanding and unvested at June 30, 2017	241		$	28.94

Shares Reserved for Future Issuance under the Stock Option Activity under the Equity Incentive Plans

The Company had the following ordinary shares reserved for future issuance under its equity incentive plans as of June 30, 2017:

	Number of Shares
	(In thousands)
Share options outstanding	3,141
Non-vested restricted share awards	749
Shares authorized for future issuance	2,310
ESPP shares available for future issuance	2,572
Total shares reserved for future issuance	8,772