Share-based compensation (Tables)

3 Months Ended

Mar. 31, 2017

Share-based compensation

Schedule of share-based compensation expense

	Three months ended March 31,
	2017		2016
	(in thousands)
Cost of sales	$	657	$	546
Research and development	429		1,099
Selling, general, and administrative	3,100		2,743
Total	$	4,186	$	4,388

Summary of stock option activity

	Number of		Weighted Average
	Shares		Exercise Price
	(in thousands)
Balance - December 31, 2016	1,576		$	35.18
Granted	—		—
Exercised	—		—
Expired or forfeited	(77	)	37.40
Balance - March 31, 2017	1,499		35.06

Summary of restricted and performance shares activity

			Weighted Average
	Number of		Grant Date
	Shares		Fair Value
	(in thousands)
Balance - December 31, 2016	1,949		$	23.85
Granted	37		26.80
Released	(53	)	31.77
Forfeited	(105	)	26.66
Balance - March 31, 2017	1,828		23.88