Stockholders' equity (Tables)

12 Months Ended

Dec. 31, 2012

Stockholders' equity

Schedule of amount of shares of common stock reserved

	December 31, 2012		December 31, 2011
	(in thousands)
Outstanding stock options under the 2001 Plan		2,345		4,340
Outstanding stock options under the 2011 Plan		2,700		2,261
Shares available for grant under the 2011 Plan		2,811		1,739
Total		7,856		8,340