Florida Oncology Partners (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Outstanding lease obligation	$ 5,332,278		$ 5,332,278
Recorded investments	330,000		330,000			471,000
Florida Oncology Partners LLC Condensed Income Statement Information [Abstract]
USNC's equity in gain (loss) of Florida Oncology Partners LLC			24,000	0
Florida Oncology Partners RE, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Recorded investments	68,000		68,000
Florida Oncology Partners [Member]
Schedule of Equity Method Investments [Line Items]
Recorded investments	223,000		223,000			200,000
Ownership percentage by outside investors (in hundredths)			80.00%
Florida Oncology Partners, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Recorded investments	155,000		155,000
Notes receivable from related parties						200,000
Notes receivable interest rate (in hundredths)			10.00%
Notes receivable including accrued interest					215,000	208,000
Florida Oncology Partners LLC Condensed Income Statement Information [Abstract]
Net sales	922,000	156,000	1,483,000	156,000
Net gain (loss)	250,000	(287,000)	186,000	(287,000)
USNC's equity in gain (loss) of Florida Oncology Partners LLC	50,000	(57,000)	37,000	(57,000)
Florida Oncology Partners LLC Condensed Balance Sheet Information [Abstract]
Current assets	973,000		973,000			1,297,000
Noncurrent assets	5,296,000		5,296,000			5,467,000
Total assets	6,269,000		6,269,000			6,764,000
Current liabilities	811,000		811,000			905,000
Noncurrent liabilities	4,607,000		4,607,000			4,944,000
Equity	851,000		851,000			915,000
Total liabilities and equity	$ 6,269,000		$ 6,269,000			$ 6,764,000
Florida Oncology Partners, LLC [Member] | USNC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage (in hundredths)	20.00%		20.00%
Percentage of guarantee obligations (in hundredths)			20.00%