Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Product revenue	$ 124,477us-gaap_SalesRevenueGoodsNet	$ 118,911us-gaap_SalesRevenueGoodsNet	$ 106,447us-gaap_SalesRevenueGoodsNet
Service revenue	47,579us-gaap_SalesRevenueServicesNet	47,290us-gaap_SalesRevenueServicesNet	45,214us-gaap_SalesRevenueServicesNet
Total revenue	172,056us-gaap_SalesRevenueNet	166,201us-gaap_SalesRevenueNet	151,661us-gaap_SalesRevenueNet
Cost of sales	116,278us-gaap_CostOfGoodsAndServicesSold	108,208us-gaap_CostOfGoodsAndServicesSold	96,509us-gaap_CostOfGoodsAndServicesSold
Gross profit	55,778us-gaap_GrossProfit	57,993us-gaap_GrossProfit	55,152us-gaap_GrossProfit
Operating expenses:
Product development and engineering	20,833us-gaap_ResearchAndDevelopmentExpense	19,381us-gaap_ResearchAndDevelopmentExpense	15,344us-gaap_ResearchAndDevelopmentExpense
Selling, general and administrative	42,695	42,993	48,599
Impairment of goodwill	0	0	1,056
Total operating expenses	63,528us-gaap_OperatingExpenses	62,374us-gaap_OperatingExpenses	64,999us-gaap_OperatingExpenses
Operating loss	(7,750)us-gaap_OperatingIncomeLoss	(4,381)us-gaap_OperatingIncomeLoss	(9,847)us-gaap_OperatingIncomeLoss
Interest expense	(329)us-gaap_InterestExpense	(526)us-gaap_InterestExpense	(601)us-gaap_InterestExpense
Gain from settlement of deferred consideration obligation	0	0	2,314
Other income (loss), net	227us-gaap_OtherNonoperatingIncomeExpense	(407)us-gaap_OtherNonoperatingIncomeExpense	(54)us-gaap_OtherNonoperatingIncomeExpense
Loss from continuing operations before provision for income taxes	(7,852)	(5,314)	(8,188)
Provision (benefit) for income taxes	4,303us-gaap_IncomeTaxExpenseBenefit	1,508us-gaap_IncomeTaxExpenseBenefit	(1,013)us-gaap_IncomeTaxExpenseBenefit
Loss from continuing operations	(12,155)	(6,822)	(7,175)
Income from discontinued operations, net of income taxes of $4,588	0	0	12,839
Net income (loss)	$ (12,155)us-gaap_NetIncomeLoss	$ (6,822)us-gaap_NetIncomeLoss	$ 5,664us-gaap_NetIncomeLoss
Net income (loss) per share — basic and diluted
From continuing operations (dollars per share)	$ (1.66)	$ (0.91)	$ (0.92)
From discontinued operations (dollars per share)	$ 0.00	$ 0.00	$ 1.64
Net income (loss) per share — basic and diluted (dollars per share)	$ (1.66)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.91)us-gaap_EarningsPerShareBasicAndDiluted	$ 0.72us-gaap_EarningsPerShareBasicAndDiluted
Weighted average number of shares:
Basic (shares)	7,344	7,484	7,813
Diluted (shares)	7,344	7,484	7,817

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