Florida Oncology Partners (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2012	Sep. 30, 2010
Schedule of Equity Method Investments [Line Items]
Recorded investments	$ 295,000		$ 295,000		$ 320,000
Due from related parties	0		0		316,000
Outstanding lease obligation	3,818,000		3,818,000
FOP and FOPRE Condensed Income Statement Information [Abstract]
Patient revenue	737,000	0	737,000	0
USNC's equity in income of FOP and FOPRE	27,000	19,000	(12,000)	12,000
FOP and FOPRE [Member]
Schedule of Equity Method Investments [Line Items]
Recorded investments	161,000		161,000		151,000		200,000
Ownership percentage (in hundredths)	20.00%		20.00%
Ownership percentage by outside investors (in hundredths)			80.00%
Due from related parties	0		0		40,000
Lease term			7 years
Capital leases, amount	5,800,000		5,800,000
Maximum guarantee	1,433,000		1,433,000
Percentage of guarantee obligations (in hundredths)			25.00%
Outstanding Loan	1,466,000		1,466,000			1,534,000
Loan amount to be paid in monthly basis			8,500
Debt maturity period			120 months
Maturity date			Jun. 15, 2022
FOP and FOPRE Condensed Income Statement Information [Abstract]
Patient revenue	748,000	812,000	1,235,000	1,469,000
Net income	155,000	116,000	48,000	81,000
USNC's equity in income of FOP and FOPRE	31,000	23,000	10,000	16,000
FOP and FOPRE Condensed Balance Sheet Information [Abstract]
Current assets	740,000		740,000		653,000
Noncurrent assets	5,396,000		5,396,000		5,795,000
Total assets	6,136,000		6,136,000		6,448,000
Current liabilities	989,000		989,000		893,000
Noncurrent liabilities	4,425,000		4,425,000		4,881,000
Equity	722,000		722,000		674,000
Total liabilities and equity	$ 6,136,000		$ 6,136,000		$ 6,448,000