v2.3.0.11

Related Parties (Details) (Director [Member], USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011
Related Party Transaction [Line Items]
Related Party Transaction Amount of Assets Under Management in Defined Benefit Plans	$ 105,900,000	$ 105,900,000
Related Party Transaction Amount of Assets in Defined Contributions Plans	19,400,000	19,400,000
Related Party Transaction Percent of Assets in Defined Contribution Plan Assets	6.40%	6.40%
Defined Benefit Pension [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0.1	100,000
Trinity [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	110,900,000	110,900,000
Related Party Transaction, Expenses from Transactions with Related Party	$ 100,000	$ 200,000

X

- Definition

Expenses recognized during the period resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 57
-Paragraph 2
-Subparagraph c
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amounts Invested in Defined Contribution Plan Mutual Fund Managed by a Director's Investment Advisory Firm

+ Details

Name:	utr_AmountsInvestedInDefinedContributionPlanMutualFundManagedByDirectorsInvestmentAdvisoryFirm
Namespace Prefix:	utr
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amounts Invested in Defined Contribution Plan Mutual Fund Managed by a Director's Investment Advisory Frim, Percentage of Total Defined Contribution Plan Investments

+ Details

Name:	utr_AmountsInvestedInDefinedContributionPlanMutualFundManagedByDirectorsInvestmentAdvisoryFirmPercentageOfTotalDefinedContributionPlanInvestments
Namespace Prefix:	utr
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Investment Assets Managed by a Directors Investment Advisory Firm

+ Details

Name:	utr_InvestmentAssetsManagedByDirectorsInvestmentAdvisoryFirm
Namespace Prefix:	utr
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Related Party Transaction Amount of Assets Under Management in Defined Benefit Plans

+ Details

Name:	utr_RelatedPartyTransactionAmountOfAssetsUnderManagementInDefinedBenefitPlans
Namespace Prefix:	utr
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant