CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,104,000	$ 1,053,000
Accounts receivable	638,000us-gaap_AccountsReceivableNetCurrent	277,000us-gaap_AccountsReceivableNetCurrent
Due from related parties	32,000us-gaap_DueFromRelatedPartiesCurrent	8,000us-gaap_DueFromRelatedPartiesCurrent
Elekta refund due	115,000usnu_ElektaRefundDue	115,000usnu_ElektaRefundDue
Other current assets	50,000us-gaap_OtherAssetsCurrent	72,000us-gaap_OtherAssetsCurrent
Total current assets	1,939,000us-gaap_AssetsCurrent	1,525,000us-gaap_AssetsCurrent
Investments in unconsolidated entities	338,000us-gaap_EquityMethodInvestments	323,000us-gaap_EquityMethodInvestments
Gamma knife (net of accumulated depreciation of $634,000 in 2015 and $475,000 in 2014)	3,801,000usnu_GammaKnifeNet	3,960,000usnu_GammaKnifeNet
Leasehold improvements (net of accumulated amortization of $276,000 in 2015 and $197,000 in 2014)	1,904,000	1,643,000
Total property and equipment	5,705,000us-gaap_PropertyPlantAndEquipmentNet	5,603,000us-gaap_PropertyPlantAndEquipmentNet
TOTAL ASSETS	7,982,000us-gaap_Assets	7,451,000us-gaap_Assets
Current liabilities:
Obligations under capital lease - current portion	903,000	821,000
Deferred tax liability- current portion	136,000us-gaap_DeferredTaxLiabilitiesCurrent	92,000us-gaap_DeferredTaxLiabilitiesCurrent
Accounts payable and accrued expenses	455,000	96,000
Deferred revenue	207,000us-gaap_DeferredRevenueCurrent	48,000us-gaap_DeferredRevenueCurrent
Due to related parties	13,000us-gaap_DueToRelatedPartiesCurrent	13,000us-gaap_DueToRelatedPartiesCurrent
Total current liabilities	1,714,000us-gaap_LiabilitiesCurrent	1,070,000us-gaap_LiabilitiesCurrent
Obligations under capital lease - net of current portion	3,609,000	3,838,000
Deferred tax liability - net of current portion	154,000	150,000
Guarantee liability	15,000us-gaap_OtherLiabilitiesNoncurrent	0us-gaap_OtherLiabilitiesNoncurrent
Asset retirement obligations	448,000	431,000
Total liabilities	5,940,000us-gaap_Liabilities	5,489,000us-gaap_Liabilities
Commitments and contingencies
STOCKHOLDERS' EQUITY
Common stock - par value $.01; 25,000,000 shares authorized; 7,797,185 shares issued and outstanding at March 31, 2015 and December 31, 2014.	78,000us-gaap_CommonStockValue	78,000us-gaap_CommonStockValue
Additional paid-in capital	3,100,000	3,100,000
Accumulated deficit	(1,136,000)	(1,216,000)
Total stockholders' equity	2,042,000us-gaap_StockholdersEquity	1,962,000us-gaap_StockholdersEquity
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 7,982,000	$ 7,451,000

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

Name:	us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant