Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

+ Details

Name:	us-gaap_DebtInstrumentFrequencyOfPeriodicPayment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

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

- Definition

Indicates type of variable interest rate on debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147481139/470-20-50-4

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_LongTermDebtAndCapitalLeaseObligationsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Lease term for sale and leaseback transaction, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479741/842-40-50-2

+ Details

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

- Definition

The number of consecutive, periodic payment installments in which the debt is to be repaid.

+ References

No definition available.

+ Details

Name:	usea_DebtInstrumentNumberOfConsecutivePaymentInstallments
Namespace Prefix:	usea_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Term of the interest rate that fluctuates over time as a result of an underlying benchmark interest rate or index, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	usea_DebtInstrumentTermOfVariableRate
Namespace Prefix:	usea_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount of financial liability at time of sale and leaseback agreement.

+ References

No definition available.

+ Details

Name:	usea_FinancialLiabilityFaceAmount
Namespace Prefix:	usea_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Optional additional lease term for sale and leaseback transaction, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	usea_SaleAndLeasebackOptionalAdditionalLeaseTerm
Namespace Prefix:	usea_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Additional lease term for sale and leaseback transaction, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	usea_SaleLeasebackTransactionAdditionalLeaseTerm
Namespace Prefix:	usea_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=usea_SaleAndLeasebackAgreementWithVillageSevenCoLtdAndV7FuneIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
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Long-Term Debt and Other Financial Liabilities, Village Seven Sale and Leaseback (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) Installment	Feb. 22, 2024 USD ($)	Dec. 31, 2023 USD ($)
Long-Term Debt and Other Financial Liabilities [Abstract]
Balance outstanding	$ 78,753		$ 64,534
Village Seven Sale and Leaseback [Member]
Long-Term Debt and Other Financial Liabilities [Abstract]
Financing amount		$ 13,800
Term of bareboat charter	4 years
Additional term of bareboat charter	2 years
Number of consecutive payment installments \| Installment	48
Frequency of periodic payment	monthly
Installment payment	$ 192
Optional additional term of bareback charter	2 years
Term of variable rate	3 months
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	usea:TermSecuredOvernightFinancingRateSOFRMember
Margin on variable rate	2.65%
Balance outstanding	$ 11,883
Village Seven Sale and Leaseback [Member] \| Maximum [Member]
Long-Term Debt and Other Financial Liabilities [Abstract]
Number of consecutive payment installments \| Installment	72