CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
ASSETS
Accounts receivable, allowance	$ 14,368	$ 17,751
PROPERTY, EQUIPMENT AND FACILITIES - accumulated depreciation and amortization	147,410	137,834
OTHER ASSETS :
Noncurrent receivables, allowance	$ 835	$ 1,078
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	29,999,684	29,659,457
Common stock, shares outstanding (in shares)	29,999,684	29,659,457
Treasury stock, shares (in shares)	5,910,541	5,910,541