Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Fair Value Measurements [Line Items]
Contingent consideration	$ 562,000	$ 17,433,000	$ 562,000	$ 17,433,000	$ 13,325,000	$ 15,400,000	$ 19,663,000
Contingent consideration, potential cash payment	23,000,000		23,000,000
Risk-adjusted discount rate to estimate fair value of contingent consideration			20.00%
Estimation of fair value of contingent consideration volatility rate			40.00%
Risk-free rate in the fair value measurement of the contingent consideration			0.13%
Counterparty risk percentage used in the fair value measurement of the contingent consideration			5.00%
Contingent consideration, fair value at aquisition date		18,870,000		18,870,000
Change in fair value of contingent consideration	(12,773,000)	(2,231,000)	(14,860,000)	(1,423,000)
Product distribution agreement, term			5 years
NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration	43,000,000		43,000,000
Contingent consideration, maximum increase			10,000,000
Contingent consideration, maximum decrease			10,000,000
Earn out provision, days due after completion of audit				20 days
Minimum [Member] | NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration, payment upon change-in-control			11,500,000
Maximum [Member]
Fair Value Measurements [Line Items]
Product distribution agreement, renewal term			5 years
Maximum [Member] | NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration, payment upon change-in-control			23,000,000
Contingent Consideration By Revenue [Member] | Minimum [Member] | NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration, potential future revenue			94,200,000
Contingent consideration, potential cash payment	9,200,000		9,200,000
Contingent Consideration By Revenue [Member] | Maximum [Member] | NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration, potential future revenue			117,800,000
Contingent consideration, potential cash payment	11,500,000		11,500,000
Contingent Consideration By EBITDA [Member] | Minimum [Member] | NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration, potential cash payment	17,200,000		17,200,000
Contingent consideration, potential earnings before income taxes, depreciation, and amortization			91,800,000
Contingent Consideration By EBITDA [Member] | Maximum [Member] | NovaMed [Member]
Fair Value Measurements [Line Items]
Contingent consideration, potential cash payment	21,500,000		21,500,000
Contingent consideration, potential earnings before income taxes, depreciation, and amortization			$ 137,800,000