Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2018

Share-based Compensation [Abstract]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

The following table sets forth the stock-based compensation expense recognized in the Consolidated Statements of Income (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Cost of goods sold	$	775	$	631	$	1,470	$	1,032
Research and development	1,638		1,299		3,047		2,476
Selling, general and administrative	6,056		6,678		9,883		11,346
Stock-based compensation expense before income taxes	$	8,469	$	8,608	$	14,400	$	14,854

Stock-based compensation expense capitalized in the Consolidated Balance Sheets is as follows (in thousands):

	June 30,
	2018		2017
Capitalized in inventory	$	1,068	$	1,053