CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 867	$ 916
Accounts receivable, allowance for appeals (in dollars)	$ 9,829	$ 13,939
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	94,190,422	93,826,453
Common stock, shares outstanding	87,664,117	87,300,148
Treasury stock, shares	6,526,305	6,526,305