XML 40 R31.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Dividends Declared Per Share (Detail) - $ / shares | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023
Dividends Payable [Line Items] |  |  |  |
Dividend Amount | $ 0.425 | $ 0.405 | $ 0.85 | $ 0.81
Group One |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | Jul. 31, 2024 |
Date Paid (Payable) |  |  | Aug. 29, 2024 |
Shareholder of Record Date |  |  | Aug. 15, 2024 |
Dividend Amount |  |  | $ 0.425 |
Group Two |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | May 01, 2024 |
Date Paid (Payable) |  |  | May 31, 2024 |
Shareholder of Record Date |  |  | May 16, 2024 |
Dividend Amount |  |  | $ 0.425 |
Group Three |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | Jan. 31, 2024 |
Date Paid (Payable) |  |  | Feb. 29, 2024 |
Shareholder of Record Date |  |  | Feb. 14, 2024 |
Dividend Amount |  |  | $ 0.425 |
Group Four |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | Oct. 23, 2023 |
Date Paid (Payable) |  |  | Nov. 28, 2023 |
Shareholder of Record Date |  |  | Nov. 14, 2023 |
Dividend Amount |  |  | $ 0.405 |
Group Five |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | Jul. 26, 2023 |
Date Paid (Payable) |  |  | Aug. 28, 2023 |
Shareholder of Record Date |  |  | Aug. 14, 2023 |
Dividend Amount |  |  | $ 0.405 |
Group Six |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | Apr. 26, 2023 |
Date Paid (Payable) |  |  | May 30, 2023 |
Shareholder of Record Date |  |  | May 15, 2023 |
Dividend Amount |  |  | $ 0.405 |
Group Seven |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Declaration Date |  |  | Jan. 25, 2023 |
Date Paid (Payable) |  |  | Feb. 28, 2023 |
Shareholder of Record Date |  |  | Feb. 14, 2023 |
Dividend Amount |  |  | $ 0.405 |

X
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the declared dividend will be paid, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 + Details
Name: | us-gaap_DividendPayableDateToBePaidDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the dividend to be paid was declared, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 + Details
Name: | us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the holder must own the stock to be entitled to the dividend, in YYYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

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_DividendsPayableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupFiveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupSixMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=utl_GroupSevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |