Inventories - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]
Raw materials	$ 8,254,000	$ 10,765,000
Work in process	64,000	534,000
Finished goods	23,236,000	20,158,000
Total inventories, net	31,554,000	31,457,000
Primary Supplier [Member]
Concentration Risk [Line Items]
Minimum supplier purchase obligations	0
Notice of termination, time upon delivery	2 months
Purchases from supplier	$ 34,500,000	$ 29,200,000	$ 23,800,000