Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts	$ 6,008	$ 5,788
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	145,000	145,000
Common stock, shares issued	45,677	45,300
Common stock, shares outstanding	45,677	45,300