XML 30 R44.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified |  | 3 Months Ended |  | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 31, 2013 | Mar. 31, 2014 Federal | Dec. 31, 2013 Federal and State | Dec. 31, 2013 State and Local Jurisdiction | Dec. 31, 2013 Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items] |  |  |  |  |
Net Operating Loss carryforward assets |  |  | $ 17.4 |  | $ 6.6
NOL carryforward assets expiration date |  |  |  | 2019 | 2029
Alternative Minimum tax credit carryforwards | $ 1.5 |  |  |  |
Tax examination description |  | The Company remains subject to examination by Federal, Maine, Massachusetts, and New Hampshire tax authorities for the tax periods ended December 31, 2010; December 31, 2011; and December 31, 2012. |  |  |

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible alternative minimum tax credit carryforwards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Alternative Minimum Tax -URI http://asc.fasb.org/extlink&oid=6504908 + Details
Name: | us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition A brief description of status of the tax examination, significant findings to date, and the entity's position with respect to the findings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319 + Details
Name: | us-gaap_IncomeTaxExaminationDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_OperatingLossCarryforwardsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operating Loss Carryforward assets net of taxes. + References No definition available. + Details
Name: | utl_NetOperatingLossCarryforwards
Namespace Prefix: | utl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Net Operating Loss Carryforwards, Expiration Year + References No definition available. + Details
Name: | utl_NetOperatingLossCarryforwardsExpirationYear
Namespace Prefix: | utl_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration