Inventories (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Inventories
Raw materials	$ 29,916,000	$ 29,353,000
Finished goods	77,926,000	77,813,000
Total	107,842,000	107,166,000
Reserves for obsolete and slow-moving items	$ 2,100,000	$ 1,800,000