Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Trade Accounts receivable, allowances	$ 5,717	$ 5,869
Common Stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common Stock shares issued	87,556,248	87,556,248
Common Stock, shares outstanding	63,415,444	69,203,967
Treasury stock, shares	24,140,804	18,352,281