CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data	Sep. 30, 2011	Dec. 31, 2010
Accounts receivable, allowance for doubtful accounts	$ 6,287	$ 6,427
Preferred stock, par value	$ 0.131	$ 0.131
Preferred stock, shares authorized	20,000	20,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00	$ 0.00
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	40,483	44,086
Common stock, shares outstanding	40,483	44,086