XML 78 R60.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Pension and Postretirement Health and Life Benefits (Narrative) (Details) (Defined Benefit Pension Plans [Member], USD $) In Millions, unless otherwise specified | 6 Months Ended
--- | ---
Jun. 30, 2014
Defined Benefit Pension Plans [Member] |
Expected defined benefit plan contributions for current fiscal year | $ 28.7
Expected defined benefit plan contributions for current fiscal year under ERISA | 26.5
Expected defined benefit plan contributions for current fiscal year for non-qualified plans | 2.2
USEC contributions | 13.1
Defined Benefit Plan, Lump Sum Benefits Paid | $ 16.9

X
- Definition The increase in the fair value of plan assets from contributions made by the employer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of employer's best estimate of contributions expected to be paid to the plan in the current remaining fiscal period. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan, Lump Sum Benefits Paid + References No definition available. + Details
Name: | usu_DefinedBenefitPlanLumpSumBenefitsPaid
Namespace Prefix: | usu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Expected defined benefit plan contributions for current fiscal year for non-qualified plans + References No definition available. + Details
Name: | usu_ExpectedDefinedBenefitPlanContributionsForCurrentFiscalYearForNonQualifiedPlans
Namespace Prefix: | usu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Expected defined benefit plan contributions for current fiscal year under ERISA + References No definition available. + Details
Name: | usu_ExpectedDefinedBenefitPlanContributionsForCurrentFiscalYearUnderErisa
Namespace Prefix: | usu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant