Medical Oncology Partners (Details) - USD ($)		3 Months Ended
	Dec. 31, 2016	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2021	Dec. 23, 2016
Medical Oncology Partners [Abstract]
Carrying value of investment		$ 146,000			$ 141,000
Advances to unconsolidated entities		182,000	$ 144,000
Condensed Consolidated Income Statement Information [Abstract]
Patient revenue		0	1,061,000
Net loss		(495,000)	292,000	$ 292,000
USNC's equity in (loss) income		(133,000)	(139,000)
Condensed Consolidated Balance Sheet Information [Abstract]
Current assets		1,705,000			2,243,000
TOTAL ASSETS		3,180,000			3,688,000
Current liabilities		624,000			327,000
Deficit		2,533,000			3,327,000
TOTAL LIABILITIES AND EQUITY		3,180,000			3,688,000
MOP [Member]
Condensed Consolidated Income Statement Information [Abstract]
Patient revenue		533,000	537,000
Net loss		(188,000)	(168,000)
Condensed Consolidated Balance Sheet Information [Abstract]
Current assets		277,000			201,000
Noncurrent assets		300,000			384,000
TOTAL ASSETS		577,000			585,000
Current liabilities		3,229,000			3,109,000
Noncurrent liabilities		78,000			92,000
Deficit		(2,730,000)			(2,616,000)
TOTAL LIABILITIES AND EQUITY		$ 577,000			$ 585,000
MOP [Member]
Medical Oncology Partners [Abstract]
Equity interest percentage to be acquired by subsidiary		100.00%
Investments in unconsolidated entities		$ 450,000
Advances to unconsolidated entities		99,600	141,000
Condensed Consolidated Income Statement Information [Abstract]
USNC's equity in (loss) income	$ (12,000)	(39,000)	$ (60,000)
MOP [Member] | Other Investor [Member]
Medical Oncology Partners [Abstract]
Investments in unconsolidated entities		105,000
MOP [Member] | USNC [Member]
Medical Oncology Partners [Abstract]
Investments in unconsolidated entities		173,000
Ownership percentage						35.83%
Carrying value of investment		149,000				$ 161,000
MOP [Member] | USNC [Member] | Dr. Jaime Lozano [Member]
Medical Oncology Partners [Abstract]
Investments in unconsolidated entities		$ 345,000
Ownership percentage		76.67%
Percentage of equity interest to an additional investor as a consulting fee for services		5.00%