Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Trade accounts receivable, allowance for doubtful accounts	$ 1,683	$ 1,706
Preferred stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common Stock, Shares Authorized	29,000,000	29,000,000
Common Stock, Shares, Issued	17,549,210	17,445,687
Common Stock, Shares, Outstanding	17,549,210	17,445,687