2.4.0.8300030 - Disclosure - Other Taxes (Tables)truefalsefalse1false falsefalseFROM_Jan01_2013_TO_Jun30_2013http://www.sec.gov/CIK0000072741duration2013-01-01T00:00:002013-06-30T00:00:001true 1nu_NotesToConsolidatedFinancialStatementsAbstractnu_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Notes To Consolidated Financial Statements [Abstract]2false 2nu_StateOfConnecticutGrossEarningsTaxesTableTextBlocknu_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div><table style="border-collapse:collapse;margin-top:20px;"><tr style="height: 10px"><td style="width: 191px; text-align:left;border-color:#000000;min-width:191px;"> </td><td colspan="5" style="width: 210px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:210px;">For the Three Months Ended</td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td colspan="5" style="width: 210px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:210px;">For the Six Months Ended</td></tr><tr style="height: 10px"><td style="width: 191px; text-align:left;border-color:#000000;min-width:191px;">(Millions of Dollars)</td><td colspan="2" style="width: 100px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:100px;">June 30, 2013</td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;"> </td><td colspan="2" style="width: 100px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:100px;">June 30, 2012</td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td colspan="2" style="width: 100px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:100px;">June 30, 2013</td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;"> </td><td colspan="2" style="width: 100px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:100px;">June 30, 2012</td></tr><tr style="height: 10px"><td style="width: 191px; text-align:left;border-color:#000000;min-width:191px;">NU</td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;">$</td><td style="width: 90px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:90px;"> 33.0</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;">$</td><td style="width: 90px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:90px;"> 30.5</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;">$</td><td style="width: 90px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:90px;"> 71.4</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;">$</td><td style="width: 90px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:90px;">65.5</td></tr><tr style="height: 10px"><td style="width: 191px; text-align:left;border-color:#000000;min-width:191px;">CL&P</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 90px; text-align:right;border-color:#000000;min-width:90px;"> 29.8</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 90px; text-align:right;border-color:#000000;min-width:90px;"> 27.7</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 90px; text-align:right;border-color:#000000;min-width:90px;"> 61.8</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 90px; text-align:right;border-color:#000000;min-width:90px;">57.1</td></tr></table></div>falsefalsefalsenonnum:textBlockItemTypenaNo authoritative reference available.No definition available.false0State Of Connecticut Gross Earnings Taxes [Table Text Block]falseOther Taxes (Tables)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.nu.com/role/DisclosureOtherTaxesTables12