Note 6 - Subsequent Events (Details Textual)	May 23, 2017
Definitive Merger Agreement, Share Exchange Ratio	0.5841

The share exchange ratio pursuant to the definitive merger agreement.

No definition available.

Name:	usac_DefinitiveMergerAgreementShareExchangeRatio
Namespace Prefix:	usac_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant