Summary of Significant Accounting Policies (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Summary of significant accounting policies (Textual) [Abstract]
Oncology practice combined represented revenue	12.90%	13.50%	15.40%	8.80%
Revenue of all other clients individually			less than 5%