Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Dec. 31, 2010
CURRENT ASSETS:
Allowances for accounts receivable	$ 2,986	$ 3,534
Accumulated depreciation on property and equipment	$ 50,069	$ 46,206
EQUITY:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	35,000,000	35,000,000
Common stock, shares issued	18,426,761	18,296,959
Common stock, shares outstanding	18,426,761	18,296,959