CB Oncology Partners (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
CB Oncology Partners [Abstract]
Carrying value of investment	$ 164,000		$ 164,000
Condensed Consolidated Income Statement Information [Abstract]
Patient revenue	865,000	$ 984,000
USNC's equity in (loss) earnings	$ (30,000)	112,000
CB Oncology Partners LLC [Member]
CB Oncology Partners [Abstract]
Ownership percentage	24.00%
Advances to unconsolidated entities	$ 543,000	$ 143,000
Absorbed its shares in losses against advances	(143,000)
Carrying value of investment	543,000
Condensed Consolidated Income Statement Information [Abstract]
Patient revenue	112,000
Net loss	(341,000)
USNC's equity in (loss) earnings	(83,000)
Condensed Consolidated Balance Sheet Information [Abstract]
Current assets	107,000		0
Noncurrent assets	0		0
Total assets	107,000		0
Current liabilities	696,000		248,000
Noncurrent liabilities	0		0
Deficit	(589,000)		(248,000)
Total liabilities and equity	$ 107,000		$ 0