Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2014

Fair value measurement

Schedule of financial assets and liabilities that are measured at fair value on a recurring basis

At December 31, 2014	Level 1		Level 2		Level 3		Total
Assets:
Money market accounts	$	5,602	$	—	$	—	$	5,602
Marketable securities		—		1,614		—		1,614
Total assets	$	5,602	$	1,614	$	—	$	7,216
Liabilities:
Contingent consideration	$	—	$	—	$	131	$	131
Total liabilities	$	—	$	—	$	131	$	131

At December 31, 2013	Level 1		Level 2		Level 3		Total
Assets:
Money market accounts	$	23,683	$	—	$	—	$	23,683
Marketable securities		—		32,962		—		32,962
Total assets	$	23,683	$	32,962	$	—	$	56,645
Liabilities:
Contingent consideration	$	—	$	—	$	1,942	$	1,942
Total liabilities	$	—	$	—	$	1,942	$	1,942

Schedule of reconciliation of the beginning and ending amounts related to the fair value of contingent consideration for the Endeka and AWG acquisitions, categorized as Level 3

Beginning balance, January 1, 2013	$	—
Contingent consideration for acquisition of businesses		2,309
Change in fair value		(367	)
Balance, December 31, 2013	$	1,942
Payment of contingent consideration		(1,000	)
Change in fair value		(811	)
Balance, December 31, 2014	$	131