Stockholders' equity (Tables)

12 Months Ended

Dec. 31, 2015

Stockholders' equity

Schedule of amount of shares of common stock reserved

	December 31, 2015		December 31, 2014
	(in thousands)
Outstanding stock options under the 2001 Plan		1,220		1,525
Outstanding stock options under the 2011 Plan		2,528		2,816
Outstanding RSUs under the 2011 Plan		1,819		1,385
Shares available for grant under the 2011 Plan		5,978		4,492
Total		11,545		10,218