Trade Accounts Receivable, Net (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Receivables [Abstract]
Trade accounts receivable	$ 131,323	$ 92,413	$ 122,328
Allowance for doubtful accounts	(836)	(945)	(1,384)
Allowance for sales discounts and returns	(2,992)	(1,451)	(2,049)
Trade accounts receivable, net	$ 127,495	$ 90,017	$ 118,895