Revenue from Contracts with Customers (ASC 606) Impact of New Revenue Guidance on Financial Statement Line Items (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Financial Statement Impact of Adopting ASC 606 [Line Items]
Sales Revenue, Goods, Net	$ 16,367,000	$ 14,169,000	$ 46,521,000	$ 43,355,000
Sales Revenue, Services, Net	27,150,000	26,281,000	80,489,000	77,755,000
Revenue, Net	43,517,000	40,450,000	127,010,000	121,110,000
Cost of Goods Sold	9,767,000	9,578,000	28,784,000	29,412,000
Cost of Services	15,376,000	13,374,000	44,690,000	39,736,000
Research and Development Expense	3,789,000	3,990,000	11,288,000	11,698,000
Selling and Marketing Expense	8,421,000	8,234,000	25,856,000	25,098,000
General and Administrative Expense	7,084,000	7,075,000	21,679,000	22,805,000
Costs and Expenses	44,437,000	42,251,000	132,297,000	128,749,000
Operating Income (Loss)	(920,000)	(1,801,000)	(5,287,000)	(7,639,000)
Net interest and other expense	(93,000)	(354,000)	(455,000)	(911,000)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(1,013,000)	(2,155,000)	(5,742,000)	(8,550,000)
Income tax expense	161,000	283,000	668,000	799,000
Cash, Cash Equivalents, and Short-term Investments	33,236,000		33,236,000			$ 42,915,000
Accounts receivable, net of allowance for doubtful accounts of $2,786 and $2,852 as of September 30, 2018 and December 31, 2017, respectively	28,971,000		28,971,000			28,316,000
Inventories	24,676,000		24,676,000			22,732,000
Current contract assets	3,460,000		3,460,000		$ 3,205,000	0
Prepaid Expense and Other Assets	3,741,000		3,741,000			3,816,000
Long-Lived Assets	96,860,000		96,860,000			92,513,000
Other Assets, Noncurrent	6,701,000		6,701,000			5,927,000
Non-current contract assets	6,626,000		6,626,000		5,963,000	0
Non-current deferred income tax asset	201,000		201,000			20,000
Assets	204,472,000		204,472,000			196,239,000
Accounts Payable and Other Accrued Liabilities, Current	58,342,000		58,342,000			36,430,000
Deferred Revenue, Current	0		0			6,919,000
Contract liabilities	10,770,000		10,770,000		11,039,000	0
Long-term contract liabilities	8,771,000		8,771,000		7,998,000	0
Deferred Income Taxes and Other Liabilities, Noncurrent	4,607,000		4,607,000
Long-term Debt, Excluding Current Maturities	20,252,000		20,252,000			44,572,000
Liabilities	102,742,000		$ 102,742,000			90,574,000
Subscriber Relationship, Estimated Life			5 years
Retained Earnings (Accumulated Deficit)	(13,575,000)		$ (13,575,000)			(4,417,000)
Common stock, additional paid-in capital, and accumulated other comprehensive loss	115,305,000		115,305,000			110,082,000
Stockholders' Equity Attributable to Parent	101,730,000		101,730,000			105,665,000
Liabilities and Equity	204,472,000		204,472,000			196,239,000
Net Income (Loss) Attributable to Parent	$ (1,174,000)	$ (2,438,000)	$ (6,410,000)	$ (9,349,000)
Earnings Per Share, Basic and Diluted	$ (0.07)	$ (0.15)	$ (0.38)	$ (0.57)
Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities			$ 12,111,000
Increase (Decrease) in Accounts Receivable and Inventories			(3,124,000)
Increase (Decrease) in Prepaid Expense and Other Assets			(1,879,000)
Increase (Decrease) in Deferred Revenue			701,000
Increase (Decrease) in Accounts Payable and Other Operating Liabilities			362,000
Net Cash Provided by (Used in) Operating Activities			1,761,000	$ 9,391,000
Deferred Revenue, Revenue Recognized	$ 1,117,000		3,525,000
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Financial Statement Impact of Adopting ASC 606 [Line Items]
Cash, Cash Equivalents, and Short-term Investments					42,915,000
Accounts receivable, net of allowance for doubtful accounts of $2,786 and $2,852 as of September 30, 2018 and December 31, 2017, respectively					28,316,000
Inventories					22,732,000
Current contract assets					3,205,000
Prepaid Expense and Other Assets					3,816,000
Long-Lived Assets					92,513,000
Other Assets, Noncurrent					5,927,000
Non-current contract assets					5,963,000
Non-current deferred income tax asset					222,000
Assets					205,609,000
Accounts Payable and Other Accrued Liabilities, Current					36,430,000
Deferred Revenue, Current					0
Contract liabilities					11,039,000
Long-term contract liabilities					7,998,000
Long-term Debt, Excluding Current Maturities					44,572,000
Liabilities					102,692,000
Retained Earnings (Accumulated Deficit)					(7,165,000)
Common stock, additional paid-in capital, and accumulated other comprehensive loss					110,082,000
Stockholders' Equity Attributable to Parent					102,917,000
Liabilities and Equity					$ 205,609,000
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Financial Statement Impact of Adopting ASC 606 [Line Items]
Cash, Cash Equivalents, and Short-term Investments						0
Accounts receivable, net of allowance for doubtful accounts of $2,786 and $2,852 as of September 30, 2018 and December 31, 2017, respectively						0
Inventories						0
Current contract assets						3,205,000
Prepaid Expense and Other Assets						0
Long-Lived Assets						0
Other Assets, Noncurrent						0
Non-current contract assets						5,963,000
Non-current deferred income tax asset						202,000
Assets	10,241,000		10,241,000			9,370,000
Accounts Payable and Other Accrued Liabilities, Current						0
Deferred Revenue, Current						(6,919,000)
Contract liabilities						11,039,000
Long-term contract liabilities						7,998,000
Long-term Debt, Excluding Current Maturities						0
Liabilities	13,117,000		13,117,000			12,118,000
Revenues	408,000		998,000
Cost of Revenue	410,000		886,000
Retained Earnings (Accumulated Deficit)						(2,748,000)
Common stock, additional paid-in capital, and accumulated other comprehensive loss						0
Stockholders' Equity Attributable to Parent						(2,748,000)
Liabilities and Equity						$ 9,370,000
Net Income (Loss) Attributable to Parent	$ 30,000		$ 128,000
Earnings Per Share, Basic and Diluted	$ 0.00		$ (0.01)
Accounting Standards Update 2014-09 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Financial Statement Impact of Adopting ASC 606 [Line Items]
Sales Revenue, Goods, Net	$ 16,775,000		$ 47,519,000
Sales Revenue, Services, Net	27,150,000		80,489,000
Revenue, Net	43,925,000		128,008,000
Cost of Goods Sold	10,177,000		29,670,000
Cost of Services	15,376,000		44,690,000
Research and Development Expense	3,789,000		11,288,000
Selling and Marketing Expense	8,412,000		25,888,000
General and Administrative Expense	7,084,000		21,679,000
Costs and Expenses	44,838,000		133,215,000
Operating Income (Loss)	(913,000)		(5,207,000)
Net interest and other expense	(93,000)		(455,000)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(1,006,000)		(5,662,000)
Income tax expense	138,000		620,000
Cash, Cash Equivalents, and Short-term Investments	33,236,000		33,236,000
Accounts receivable, net of allowance for doubtful accounts of $2,786 and $2,852 as of September 30, 2018 and December 31, 2017, respectively	28,971,000		28,971,000
Inventories	24,676,000		24,676,000
Current contract assets	0		0
Prepaid Expense and Other Assets	3,741,000		3,741,000
Long-Lived Assets	96,860,000		96,860,000
Other Assets, Noncurrent	6,701,000		6,701,000
Non-current contract assets	0		0
Non-current deferred income tax asset	46,000		46,000
Assets	194,231,000		194,231,000
Accounts Payable and Other Accrued Liabilities, Current	58,342,000		58,342,000
Deferred Revenue, Current	6,424,000		6,424,000
Contract liabilities	0		0
Long-term contract liabilities	0		0
Deferred Income Taxes and Other Liabilities, Noncurrent	4,607,000		4,607,000
Long-term Debt, Excluding Current Maturities	20,252,000		20,252,000
Liabilities	89,625,000		89,625,000
Retained Earnings (Accumulated Deficit)	(10,699,000)		(10,699,000)
Common stock, additional paid-in capital, and accumulated other comprehensive loss	115,305,000		115,305,000
Stockholders' Equity Attributable to Parent	104,606,000		104,606,000
Liabilities and Equity	194,231,000		194,231,000
Net Income (Loss) Attributable to Parent	$ (1,144,000)		$ (6,282,000)
Earnings Per Share, Basic and Diluted	$ (0.07)		$ (0.37)
Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities			$ 12,063,000
Increase (Decrease) in Accounts Receivable and Inventories			(3,124,000)
Increase (Decrease) in Prepaid Expense and Other Assets			(961,000)
Increase (Decrease) in Deferred Revenue			(297,000)
Increase (Decrease) in Accounts Payable and Other Operating Liabilities			362,000
Net Cash Provided by (Used in) Operating Activities			$ 1,761,000