Schedule II - Valuation and Qualifying Accounts (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 407,000	$ 49,000
Additions charged to Expense or Revenue	125,000	27,000
Deductions and write-offs	(6,000)	0
Balance at End of Period	526,000	76,000
Allowance for product returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	215,000	89,000
Additions charged to Expense or Revenue	201,000	190,000
Deductions and write-offs	(111,000)	(167,000)
Balance at End of Period	305,000	112,000
Allowance for obsolescence
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	322,000	159,000
Additions charged to Expense or Revenue	24,000	25,000
Deductions and write-offs	(23,000)	0
Balance at End of Period	$ 323,000	$ 184,000