XML 89 R76.htm IDEA: XBRL DOCUMENT
v3.21.1

CASH, CASH EQUIVALENTS AND SHORT AND LONG TERM INVESTMENTS - Summary of Available-for-sale Investments -Additional Information (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 USD ($)
Level 3 |
Schedule of Available-for-sale Securities [Line Items] |
Estimated fair value | $ 2.1
Minimum |
Schedule of Available-for-sale Securities [Line Items] |
Maturity period of bank notes receivable | 3 months
Maximum |
Schedule of Available-for-sale Securities [Line Items] |
Maturity period of bank notes receivable | 1 year

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maturity period of bank notes receivable. + References No definition available. + Details
Name: | utsi_NotesAndLoansReceivableMaturityPeriod
Namespace Prefix: | utsi_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |