Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2015

Fair value measurement

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

At December 31, 2015	Level 1		Level 2		Level 3		Total
Assets:
Money market accounts	$	2,230	$	—	$	—	$	2,230
Total assets	$	2,230	$	—	$	—	$	2,230

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

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, 2014	$	1,942
Payment of contingent consideration		(1,000	)
Change in fair value		(811	)
Balance, December 31, 2014		131
Payment of contingent consideration		(17	)
Change in fair value		(114	)
Balance, December 31, 2015	$	—