Valuation and qualifying accounts (Tables)

12 Months Ended

Dec. 31, 2014

Valuation and qualifying accounts

Schedule of valuation and qualifying accounts

	Balance at		Additions		Changes to		Balance at
	beginning		charged to		reserve, net(1)		end of year
	of year		earnings
Year ended December 31, 2014
Allowance for doubtful accounts	$	1,051	$	577	$	39	$	1,667
Reserves for inventory		1,599		1,752		(899)		2,452
Valuation of deferred tax assets		1,395		-		205		1,600
Year ended December 31, 2013
Allowance for doubtful accounts	$	600	$	329	$	122	$	1,051
Reserves for inventory		1,199		757		(357)		1,599
Valuation of deferred tax assets		1,374		-		21		1,395
Year ended December 31, 2012
Allowance for doubtful accounts	$	1,247	$	259	$	(906)	$	600
Reserves for inventory		1,288		715		(804)		1,199
Valuation of deferred tax assets		830		-		544		1,374