Borrowing Arrangements (Details) (USD $) | 12 Months Ended |
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | $1,258,500,000 | $1,210,100,000 | ' |
Current maturities of long-term debt | 0 | -105,000,000 | ' |
Unamortized debt premium and discount - net | -1,400,000 | -1,700,000 | ' |
Long-term debt - net of current maturities and debt subject to tender | 1,257,100,000 | 1,103,400,000 | ' |
Letters of Credit Outstanding, Amount | 41,700,000 | ' | ' |
Long-term debt death put repayments | 0 | 800,000 | 1,800,000 |
Maturities of long term debt [Abstract] | ' | ' | ' |
Debt maturing within 12 months following date of latest balance sheet | 0 | ' | ' |
Debt maturing within two years following date of latest balance sheet | 104,800,000 | ' | ' |
Debt maturing within three years following date of latest balance sheet | 13,000,000 | ' | ' |
Debt maturing within four years following date of latest balance sheet | 0 | ' | ' |
Debt maturing within five years following date of latest balance sheet | 100,000,000 | ' | ' |
Debt maturing thereafter 5 years following date of the latest balance sheet | 1,039,300,000 | ' | ' |
Debt guarantees [Abstract] | ' | ' | ' |
Long-term guarantees | 875,000,000 | ' | ' |
Short-term debt guarantees | 29,000,000 | ' | ' |
Covenants [Abstract] | ' | ' | ' |
Ratio of consolidated total debt to consolidated total capitalization, maximum ( in hundredths) | 'not exceed 65 percent | ' | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 875,000,000 | 821,600,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2013, 5.25% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 100,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2015, 5.45% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 75,000,000 | 75,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2018, 5.75% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 100,000,000 | 100,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2020, 6.28% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 100,000,000 | 100,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2021, 4.67 [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | ' | ' | 55,000,000 |
Proceeds from debt issuance | ' | ' | 149,000,000 |
Fixed rate stated percentage (in hundredths) | ' | ' | 4.67% |
Maturity date | ' | ' | 30-Nov-21 |
Debt Instrument Issuance Date | ' | ' | 30-Nov-11 |
Total long term debt outstanding | 55,000,000 | 55,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2023, 3.72% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 150,000,000 | 0 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2026, 5.02% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | ' | ' | 60,000,000 |
Fixed rate stated percentage (in hundredths) | ' | ' | 5.02% |
Maturity date | ' | ' | 30-Nov-26 |
Debt Instrument Issuance Date | ' | ' | 30-Nov-11 |
Total long term debt outstanding | 60,000,000 | 60,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2028, 3.20% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 45,000,000 | 0 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2035, 6.10% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 75,000,000 | 75,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2039, 6.25% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 121,600,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2041, 5.99% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | ' | ' | 35,000,000 |
Fixed rate stated percentage (in hundredths) | ' | ' | 5.99% |
Maturity date | ' | ' | 2-Dec-41 |
Debt Instrument Issuance Date | ' | ' | 30-Nov-11 |
Total long term debt outstanding | 35,000,000 | 35,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2042, 5.00% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | ' | 100,000,000 | ' |
Proceeds from debt issuance | ' | 99,500,000 | ' |
Fixed rate stated percentage (in hundredths) | ' | 5.00% | ' |
Maturity date | ' | 3-Feb-42 | ' |
Debt Instrument Issuance Date | ' | 1-Feb-12 | ' |
Total long term debt outstanding | 100,000,000 | 100,000,000 | ' |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2036, 5.95% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Fixed rate stated percentage (in hundredths) | ' | ' | 5.95% |
Maturity date | ' | ' | 31-Dec-36 |
Total long term debt outstanding | ' | ' | 96,200,000 |
Debt Instrument Put And Call Exercise Date | ' | ' | 21-Nov-11 |
Utility Holdings [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2043, 4.25% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 80,000,000 | 0 | ' |
Utility Holdings [Member] | Senior Guaranteed Notes [Member] | 2043, 4.25% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | ' | 80,000,000 | ' |
Fixed rate stated percentage (in hundredths) | ' | 4.25% | ' |
Maturity date | ' | 5-Jun-43 | ' |
Debt Instrument Issuance Date | ' | 5-Jun-13 | ' |
Utility Holdings [Member] | Senior Guaranteed Notes [Member] | 2028, 3.20% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | ' | 45,000,000 | ' |
Fixed rate stated percentage (in hundredths) | ' | 3.20% | ' |
Maturity date | ' | 5-Jun-28 | ' |
Debt Instrument Issuance Date | ' | 5-Jun-13 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 116,000,000 | 121,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2013, Series E, 6.69% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 5,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2015, Series E, 7.15% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 5,000,000 | 5,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2015, Series E1, 6.69% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 10,000,000 | 10,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2015, Series E, 6.69% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 5,000,000 | 5,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2025, Series E, 6.53% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 10,000,000 | 10,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2027, Series E, 6.42% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 5,000,000 | 5,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2027, Series E, 6.68% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 1,000,000 | 1,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2027, Series F, 6.34% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 20,000,000 | 20,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2028, Series F, 6.36% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 10,000,000 | 10,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2028, Series F, 6.55% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 20,000,000 | 20,000,000 | ' |
Indiana Gas [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2029, Series G, 7.08% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 30,000,000 | 30,000,000 | ' |
SIGECO [Member] | First Mortgage Bonds [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 62,000,000 | ' | ' |
Proceeds from debt issuance | 60,000,000 | ' | ' |
SIGECO [Member] | First Mortgage Bonds [Member] | Tax Exempt Debt, 4.00 percent, due 2038 [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 22,200,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 4.00% | ' | ' |
Maturity date | 1-Mar-38 | ' | ' |
Debt Instrument Issuance Date | 26-Apr-13 | ' | ' |
SIGECO [Member] | First Mortgage Bonds [Member] | Tax Exempt Debt, 4.05 percent, due 2043 [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 39,600,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 4.05% | ' | ' |
Maturity date | 1-May-43 | ' | ' |
Debt Instrument Issuance Date | 26-Apr-13 | ' | ' |
SIGECO [Member] | First Mortgage Bonds [Member] | Tax Exempt Debt, 1.95 Percent [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Proceeds from debt issuance | 48,300,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 1.95% | ' | ' |
Amount of debt to be re-marketed | 49,000,000 | ' | ' |
Debt re-market date | 'August 13, 2013 | ' | ' |
SIGECO [Member] | Mortgages [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 267,500,000 | 267,500,000 | ' |
Future long term debt sinking fund fund requirements and maturities [Abstract] | ' | ' | ' |
Annual sinking fund requirement fixed percentage (in hundredths) | 1.00% | ' | ' |
Utility plant remaining unfunded under mortgage indenture | 1,200,000,000 | ' | ' |
Gross utility plant balance subject to the mortgage indenture | 2,900,000,000 | ' | ' |
SIGECO [Member] | Mortgages [Member] | 2015, 1985 Pollution Control Series A, current adjustable rate 0.15%, tax exempt, 2012 weighted average: 0.17% | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 9,800,000 | 9,800,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2016, 1986 Series, 8.875% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 13,000,000 | 13,000,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2020, 1998 Pollution Control Series B, 4.50%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 4,600,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2022, 2013 Series C, 1.95% tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 4,600,000 | 0 | ' |
SIGECO [Member] | Mortgages [Member] | 2023, 1993 Environmental Improvement Series B, 5.15%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 22,600,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2024, 2000 Environmental Improvement Series A, 4.65%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 22,500,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2024, 2013 Series D, 1.95% tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 22,500,000 | 0 | ' |
SIGECO [Member] | Mortgages [Member] | 2025, 1998 Pollution Control Series A, current adjustable rate 0.15%, tax exempt, 2012 weighted average: 0.16% | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 31,500,000 | 31,500,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2029, 1999 Senior Notes, 6.72% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 80,000,000 | 80,000,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2030, 1998 Pollution Control Series B, 5.00%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 22,000,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2037, 2013 Series E 1.95% Tax Exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 22,000,000 | 0 | ' |
SIGECO [Member] | Mortgages [Member] | 2038, 2013 Series A, 4.00% Tax Exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 22,200,000 | 0 | ' |
SIGECO [Member] | Mortgages [Member] | 2030, 1998 Pollution Control Series C, 5.35%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 22,200,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2040, 2009 Environmental Improvement Series, 5.40%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 22,300,000 | 22,300,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2041, 2007 Pollution Control Series, 5.45%, tax exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 0 | 17,000,000 | ' |
SIGECO [Member] | Mortgages [Member] | 2043, 2013 Series B 4.05% Tax Exempt [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Total long term debt outstanding | 39,600,000 | 0 | ' |
Vectren Utility Holdings Inc [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2023, 3.72% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 150,000,000 | ' | ' |
Proceeds from debt issuance | 149,100,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 3.72% | ' | ' |
Maturity date | 5-Dec-23 | ' | ' |
Debt Instrument, Offering Date | 22-Aug-13 | ' | ' |
Debt Instrument Issuance Date | 5-Dec-13 | ' | ' |
Vectren Utility Holdings Inc [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2028, 3.20% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 45,000,000 | ' | ' |
Proceeds from debt issuance | 44,800,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 3.20% | ' | ' |
Maturity date | 5-Jun-28 | ' | ' |
Debt Instrument Issuance Date | 5-Jun-13 | ' | ' |
Vectren Utility Holdings Inc [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2039, 6.25% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 121,600,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 6.25% | ' | ' |
Maturity date | 31-Dec-39 | ' | ' |
Current maturities of long-term debt | -121,600,000 | ' | ' |
Debt redemption date | 1-Apr-13 | ' | ' |
Vectren Utility Holdings Inc [Member] | Fixed Rate Senior Unsecured Notes [Member] | 2043, 4.25% [Member] | ' | ' | ' |
Long term debt [Abstract] | ' | ' | ' |
Debt Issuance | 80,000,000 | ' | ' |
Proceeds from debt issuance | $79,600,000 | ' | ' |
Fixed rate stated percentage (in hundredths) | 4.25% | ' | ' |
Maturity date | 5-Jun-43 | ' | ' |
Debt Instrument Issuance Date | 5-Jun-13 | ' | ' |