Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets
Net of allowance on accounts receivable	$ 14,161,000	$ 13,070,000
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	70,000,000	70,000,000
Common stock, shares outstanding	31,289,614	31,039,770