CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue recognized	$ 0.1	$ 0.3	$ 0.4
Selling expenses recognized	$ 1.3	$ 3.5	$ 9.2
Ordinary share, par value (in dollars per share)	$ 0.015	$ 0.015
Reverse split stock			one-for-four

Face amount or stated value per share of common stock.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-8

+ Details

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Description of the reverse stock split arrangement. Also provide the retroactive effect given by the reverse split that occurs after the balance sheet date but before the release of financial statements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 4.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-4

+ Details

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

- Definition

Provision for doubtful accounts, net of reversals.

+ References

No definition available.

+ Details

Name:	utsi_ProvisionForDoubtfulAccountsNetOfReversals
Namespace Prefix:	utsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration