Schedule II - Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 49,000	$ 19,000	$ 21,000
Additions charged to Expense or Revenue	391,000	57,000	58,000
Deductions and write-offs	(33,000)	(27,000)	(60,000)
Balance at End of Year	407,000	49,000	19,000
Allowance for product returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	89,000	88,000	39,000
Additions charged to Expense or Revenue	917,000	394,000	189,000
Deductions and write-offs	(791,000)	(393,000)	(140,000)
Balance at End of Year	215,000	89,000	88,000
Allowance for obsolescence
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	159,000	53,000	29,000
Additions charged to Expense or Revenue	213,000	106,000	30,000
Deductions and write-offs	(50,000)	0	(6,000)
Balance at End of Year	$ 322,000	$ 159,000	$ 53,000