CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED BALANCE SHEETS [Abstract]
Accounts receivable, allowance for doubtful accounts and billing adjustments	$ 2,777	$ 2,175
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred Stock, shares issued (in shares)	0	0
Preferred Stock, shares outstanding (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized (in shares)	75,000,000	75,000,000
Common Stock, shares issued (in shares)	37,012,250	36,398,811
Common Stock, shares outstanding (in shares)	37,012,250	36,398,811