XML 54 R35.htm IDEA: XBRL DOCUMENT v2.4.1.9

Dividends Declared Per Share (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Dividends Payable [Line Items]
Dividend Amount	$ 0.350us-gaap_CommonStockDividendsPerShareDeclared	$ 0.345us-gaap_CommonStockDividendsPerShareDeclared
Group One
Dividends Payable [Line Items]
Declaration Date	Apr. 22, 2015
Date Paid (Payable)	May 28, 2015
Shareholder of Record Date	May 14, 2015
Dividend Amount	$ 0.350us-gaap_CommonStockDividendsPerShareDeclared / us-gaap_DividendsAxis = utl_GroupOneMember
Group Two
Dividends Payable [Line Items]
Declaration Date	Jan. 26, 2015
Date Paid (Payable)	Feb. 27, 2015
Shareholder of Record Date	Feb. 13, 2015
Dividend Amount	$ 0.350us-gaap_CommonStockDividendsPerShareDeclared / us-gaap_DividendsAxis = utl_GroupTwoMember
Group Three
Dividends Payable [Line Items]
Declaration Date	Oct. 21, 2014
Date Paid (Payable)	Nov. 28, 2014
Shareholder of Record Date	Nov. 14, 2014
Dividend Amount	$ 0.345us-gaap_CommonStockDividendsPerShareDeclared / us-gaap_DividendsAxis = utl_GroupThreeMember
Group Four
Dividends Payable [Line Items]
Declaration Date	Jul. 22, 2014
Date Paid (Payable)	Aug. 29, 2014
Shareholder of Record Date	Aug. 15, 2014
Dividend Amount	$ 0.345us-gaap_CommonStockDividendsPerShareDeclared / us-gaap_DividendsAxis = utl_GroupFourMember
Group Five
Dividends Payable [Line Items]
Declaration Date	Apr. 22, 2014
Date Paid (Payable)	May 29, 2014
Shareholder of Record Date	May 15, 2014
Dividend Amount	$ 0.345us-gaap_CommonStockDividendsPerShareDeclared / us-gaap_DividendsAxis = utl_GroupFiveMember
Group Six
Dividends Payable [Line Items]
Declaration Date	Jan. 16, 2014
Date Paid (Payable)	Feb. 28, 2014
Shareholder of Record Date	Feb. 14, 2014
Dividend Amount	$ 0.345us-gaap_CommonStockDividendsPerShareDeclared / us-gaap_DividendsAxis = utl_GroupSixMember

X

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ 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 CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ 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 CCYY-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

- 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_GroupFiveMember
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_GroupOneMember
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_GroupThreeMember
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: