Acquisition (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Apr. 18, 2011
Date of acquisition	Apr. 18, 2011
Date of acquisition agreement	Apr. 18, 2011
Purchase price allocation, cash paid			$ 24,578,000
Stock Issued During Period, Shares, Acquisitions		8,298,110
Purchase price allocation, shares of common stock			31,530,000
Contingent consideration maximum revenue threshold for full amount of cash	117,800,000
Earn out payments business days due	20 days
Revenue volatility		40.00%
Risk free interest rate		0.15%
Earn out discount rate including counter party risk		5.00%
Business acquisition, purchase price	74,978,000		74,978,000
Initial estimated fair value of the contingent considertion	18,900,000
Contingent consideration at estimated fair value	0	15,400,000	(18,870,000)
Non cash gain on contingent consideration	15,400,000	3,500,000
Intangible assets, useful life	13 years 6 months
Discount rate	29.00%	20.00%
Acquisition-related transaction costs		3,800,000
Maximum [Member]
Contingent Consideration Allowable Increase Decrease Of Earn Out Payments	10,000,000
Minimum [Member]
Contingent Consideration Allowable Increase Decrease Of Earn Out Payments	(10,000,000)
Potential Revenues [Member]
Contingent Consideration Minimum Revenue Threshold For Cash Paymen	94,200,000
Potential Revenues [Member] | Maximum [Member]
Contingent consideration, potential cash payment	11,500,000
Potential Revenues [Member] | Minimum [Member]
Contingent consideration, potential cash payment	9,200,000
Potential EBITDA [Member]
Contingent Consideration Minimum Adjusted EBITDA Threshold For Cash Payment	91,800,000
Contingent consideration maximum adjusted EBITDA threshold for full amount of cash payment	137,800,000
Potential EBITDA [Member] | Maximum [Member]
Contingent consideration, potential cash payment	21,500,000
Potential EBITDA [Member] | Minimum [Member]
Contingent consideration, potential cash payment	17,200,000
NovaMed [Member]
Contingent consideration	$ 43,000,000