Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Summary of option activity

				Weighted-Average
	Outstanding Options			Remaining	Aggregate
	Number of	Weighted-Average		Contractual	Intrinsic
	Shares	Exercise Price		Life	Value
	(In thousands)			(In years)	(In thousands)
Balance at December 31, 2015	3,630	$	23.80
Options granted	716	$	26.98
Options exercised	(603)	$	19.66
Options forfeited	(47)	$	28.23
Options expired	(90)	$	23.88
Balance at December 31, 2016	3,606	$	25.07	5.4	$	17,518
Exercisable at December 31, 2016	2,629	$	23.91	4.2	$	15,815
Vested and expected to vest at December 31, 2016	3,543	$	25.02	5.4	$	17,403

Summary of RSU activity

		Weighted-Average
	Number of	Grant Date Fair
	Shares	Value
	(In thousands)
Balance at December 31, 2015	682	$	30.18
RSUs granted	605	$	27.50
RSUs vested	(319)	$	30.27
RSUs cancelled	(97)	$	29.02
Balance at December 31, 2016	871	$	28.42

Schedule of share-based compensation expense

	Year Ended December 31,
	2016		2015		2014
	(In thousands)
Cost of product revenues	$	590	$	525	$	497
Research and development		4,934		4,228		4,143
Selling and marketing		5,551		4,526		4,822
General and administrative		7,228		6,726		7,076
Total	$	18,303	$	16,005	$	16,538

Schedule of weighted-average fair values and assumptions used in calculation of fair value of stock options and employee stock purchase plan

	Year Ended December 31,
	2016			2015			2014
Expected volatility:
Stock options		44	%		44	%		44	%
ESPP		44	%		35	%		37	%
Risk-free interest rate:
Stock options		1.36	%		1.66	%		1.97	%
ESPP		0.47	%		0.10	%		0.08	%
Expected life in years:
Stock options		6.10			5.94			6.61
ESPP		0.50			0.50			0.50
Weighted-average fair value:
Stock options	$	11.73		$	13.37		$	14.13
ESPP	$	7.35		$	6.99		$	7.24

Performance-Based Vesting

Summary of RSU activity

		Weighted-Average
	Number of	Grant Date Fair
	Shares	Value
	(In thousands)
Balance at December 31, 2015	6	$	27.21
PVRSUs granted	12	$	28.09
PVRSUs vested	(6)	$	27.21
PVRSUs cancelled	(12)	$	28.09
Balance at December 31, 2016	—	$	—