Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Condensed Consolidated Balance Sheets [Abstract]
Trade receivables, allowances	$ 7,259	$ 9,497	$ 10,462
Common stock, par value	$ 0.01	$ 0.01	$ 0.01
Common stock, shares outstanding	45,774,157	45,298,038	45,165,530