Note 2 - Acquisitions (Details Textual) - Northern Plains [Member]		9 Months Ended
Aug. 01, 2017 shares	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Business Acquisition, Equity Interest Issued or Issuable, Exchange Ratio	0.5841
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares \| shares	1,644,458
Present Value of Future Insurance Profits, Weighted Average Amortization Period	30 years
Proceeds from Third Party Administrative (TPA) Fees Received		$ 31,250	$ 50,781
Business Combination, Acquisition Related Costs		201,577
Business Acquisition, Pro Forma Information, Adjustments for Amortization of VOBA and Elimination of DAC Amortization		$ 78,379	$ 21,498

Number of shares of equity interests issued or issuable to acquire entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e1043-128460

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Weighted average amortization period of present value of future profits of insurance contract acquired in business combination, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 805
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6918812&loc=d3e30762-158568

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the exchange ratio for shares of equity interests issued or issuable to acquire entity.

+ References

No definition available.

+ Details

Name:	usac_BusinessAcquisitionEquityInterestIssuedOrIssuableExchangeRatio
Namespace Prefix:	usac_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of adjustments for the amortization of VOBA and elimination of DAC amortization for the period, recorded by the acquiree, if the business combination or combinations had been completed at the beginning of the period.

+ References

No definition available.

+ Details

Name:	usac_BusinessAcquisitionProFormaInformationAdjustmentsForAmortizationOfVOBAAndEliminationOfDACAmortization
Namespace Prefix:	usac_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash received for third party administrative fees during the period.

+ References

No definition available.

+ Details

Name:	usac_ProceedsFromThirdPartyAdministrativeTPAFeesReceived
Namespace Prefix:	usac_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=usac_NorthernPlainsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: