XML 69 R54.htm IDEA: XBRL DOCUMENT v2.4.1.9
Summary Of Significant Accounting Policies (Significant Unobservable Inputs in Asset Valuation) (Details) (Vermont Yankee [Member])
Jul. 31, 2013
Mar. 31, 2012
Weighted average cost of capital, Weighted Average 7.50%etr_WeightedAverageCostOfCapitalUsedInAssetValuation 7.80%etr_WeightedAverageCostOfCapitalUsedInAssetValuation
Long-term pre-tax operating margin (cash basis), Weighted Average 7.00%etr_OperatingMarginUsedInAssetValuation 7.20%etr_OperatingMarginUsedInAssetValuation
Minimum [Member]
    
Weighted average cost of capital, Range   7.50%etr_WeightedAverageCostOfCapitalUsedInAssetValuationRange
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_StatementBusinessSegmentsAxis
= etr_VermontYankeeMember
Long-term pre-tax operating margin (cash basis), Range   6.10%etr_OperatingMarginUsedInAssetValuationRange
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_StatementBusinessSegmentsAxis
= etr_VermontYankeeMember
Maximum [Member]
    
Weighted average cost of capital, Range   8.00%etr_WeightedAverageCostOfCapitalUsedInAssetValuationRange
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_StatementBusinessSegmentsAxis
= etr_VermontYankeeMember
Long-term pre-tax operating margin (cash basis), Range   7.80%etr_OperatingMarginUsedInAssetValuationRange
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_StatementBusinessSegmentsAxis
= etr_VermontYankeeMember