Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Allowance for trade accounts receivable	$ 1,997	$ 3,078
LIABILITIES AND STOCKHOLDERS' EQUITY
Unamortized discount or premium on notes, long-term debt	$ 1,991	$ 9,425
Stockholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	42,432,309	42,394,809
Common stock, shares outstanding	42,394,955	41,310,447
Treasury stock, shares	37,354	1,084,362