CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances	$ 5,223	$ 6,194
Preferred Stock, par value (in dollars per share)	$ 0	$ 0
Preferred Stock, authorized shares (in shares)	15,000	15,000
Preferred Stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	60,000	60,000
Common stock, shares issued (in shares)	41,474	41,042
Treasury stock, shares (in shares)	8,903	8,903