Significant Accounting Policies (Details 1)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Percentage of net service revenue
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
Medicare [Member]
Percentage of net service revenue
Percentage of net service revenue	77.20%	79.40%	77.90%	79.70%
Medicaid [Member]
Percentage of net service revenue
Percentage of net service revenue	1.70%	2.40%	1.90%	2.30%
Other [Member]
Percentage of net service revenue
Percentage of net service revenue	21.10%	18.20%	20.20%	18.00%