Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Allowance for doubtful accounts	$ 2,300,000	$ 1,800,000
Stockholders' equity:
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	23,423,052	23,319,492
Common stock, shares outstanding	23,378,368	23,256,897
Treasury stock, shares	44,684	62,595