Summary of Significant Accounting Policies (Schedule of ResponseDX Revenue) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net revenue	$ 5,313,914	$ 3,835,006	$ 10,938,105	$ 7,816,651
ResponseDX [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net revenue	3,106,077	2,834,185	6,288,574	5,785,987
ResponseDX [Member] | Private Payor [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net revenue	2,027,604	1,526,684	3,865,886	3,012,327
ResponseDX [Member] | Other Payor [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net revenue	0	512	0	6,353
Medicare [Member] | ResponseDX [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net revenue	$ 1,078,473	$ 1,306,989	$ 2,422,688	$ 2,767,307