Boca Oncology Partners (Details)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011 USD ($)	Sep. 30, 2023 USD ($) ft²	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) ft²	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Boca Oncology Partners [Abstract]
Recorded investments			$ 187,000		$ 187,000		$ 157,000
Condensed Income Statement Information [Abstract]
Net income			(150,000)	$ (378,000)	(788,000)	$ (2,167,000)	(1,572,000)
USNC's equity in (loss) income			2,000	(156,000)	(266,000)	(1,287,000)
Condensed Balance Sheet Information [Abstract]
Current assets			579,000		579,000		1,555,000
TOTAL ASSETS			871,000		871,000		1,747,000
Current liabilities			191,000		191,000		280,000
Equity			669,000		669,000		1,456,000	$ 3,028,000
TOTAL LIABILITIES AND EQUITY			871,000		871,000		1,747,000
Boca Oncology Partners RE, LLC ("BOPRE") [Member]
Condensed Income Statement Information [Abstract]
Rental income			0	0	0	0
Net income			7,000	16,000	16,000	52,000
Condensed Balance Sheet Information [Abstract]
Current assets			48,000		48,000		123,000
Noncurrent assets			757,000		757,000		757,000
TOTAL ASSETS			805,000		805,000		880,000
Current liabilities			0		0		0
Noncurrent liabilities			0		0		0
Equity			805,000		805,000		880,000
TOTAL LIABILITIES AND EQUITY			$ 805,000		$ 805,000		880,000
Boca Oncology Partners, LLC [Member]
Boca Oncology Partners [Abstract]
Area of real estate property (in square foot) | ft²			6,000		6,000
Boca Oncology Partners RE, LLC ("BOPRE") [Member]
Boca Oncology Partners [Abstract]
Ownership percentage			23.10%		23.10%
Recorded investments			$ 187,000		$ 187,000		$ 157,000
Condensed Income Statement Information [Abstract]
USNC's equity in (loss) income			$ 2,000	$ 2,000	$ 2,000	$ 8,000
Boca Oncology Partners RE, LLC ("BOPRE") [Member] | Boca West IMP [Member]
Boca Oncology Partners [Abstract]
Percentage of interest in medical office building		20.00%
Ownership percentage	23.75%
Additional investor purchased ownership percentage	3.75%
BOP and BOPRE [Member]
Boca Oncology Partners [Abstract]
Area of real estate property (in square foot) | ft²			32,000		32,000
Investments in unconsolidated entities		$ 225,000
Ownership percentage		22.50%