Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Net revenues:
Product revenues	$ 138,175	$ 133,342
Service revenues	6,745	8,405
Total net revenues	144,920	141,747
Cost of revenues:
Cost of product revenues	27,179	32,084
Cost of service revenues	4,151	5,790
Amortization expense	17,370	18,270
Total cost of revenues	48,700	56,144
Research and development expense	10,924	11,091
Sales and marketing expense	44,088	41,431
General and administrative expense	20,098	19,357
Shipping and handling costs	1,056	1,469
Depreciation and amortization expense	3,868	4,209
Total costs and expenses	128,734	133,701
Income before interest, other income (expense) and income taxes	16,186	8,046
Net interest income (expense):
Interest income	13	4
Interest expense	(13,994)	(17,663)
Net interest expense	(13,981)	(17,659)
Loss on extinguishment of debt	(4,016)	(922)
Other income, net	679	1,180
Loss before income taxes	(1,132)	(9,355)
Income tax expense	(193)	(600)
Net loss	(1,325)	(9,955)
Other comprehensive income (loss):
Net pension gain (loss)	925	(1,930)
Amortization of net pension loss	223	86
Comprehensive loss	$ (177)	$ (11,799)
Net loss per common share:
Basic net loss per common share	$ (0.03)	$ (0.22)
Diluted net loss per common share	$ (0.03)	$ (0.22)
Average number of common shares and equivalents outstanding:
Basic	45,550	45,636
Diluted	45,550	45,636