Inventories (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Inventories [Abstract]
Finished goods	$ 22,886	$ 24,657
Work in process	3,883	3,743
Raw materials and supplies	29,213	24,095
Inventories, net	55,982	52,495
Allowance for excess and obsolete inventory [Roll Forward]
Balance at beginning of year	2,244	1,239	1,612
Provision	2,089	2,385	598
Charges	(1,383)	(1,380)	(971)
Balance at end of year	$ 2,950	$ 2,244	$ 1,239