v2.4.0.8

Risk Management Activities Risk Management Activities (Offsetting Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified | Jun. 30, 2013 | Dec. 31, 2012
--- | --- | ---
Offsetting Assets and Liabilities [Line Items] |  |  |  |
Gross Amounts of Recognized Assets | $ 73.5 |  | $ 148.2 |
Gross Amounts Offset in the Statement of Financial Position | 0 |  | 0 |
Net Amounts of Assets Presented in the Statement of Financial Position | 73.5 |  | 148.2 |
Gross Amounts Not Offset in the Statement of Financial Position | (37.4) |  | (72.7) |
Net Derivative Position - Assets | 36.1 |  | 75.5 |
Gross Amounts of Recognized Liabilities | (52.5) |  | (115.5) |
Gross Amounts Offset in the Statement of Financial Position-Liabilities | 0 |  | 0 |
Net Amounts of Liabilities Presented in the Statement of Financial Position | (52.5) |  | (115.5) |
Gross Amounts Not Offset in the Statement of Financial Position- Liabilities | 37.4 |  | 72.7 |
Net Derivative Position-Liabilities | (15.1) |  | (42.8) |
Counterparty A [Member] |  |  |  |
Offsetting Assets and Liabilities [Line Items] |  |  |  |
Gross Amounts of Recognized Assets | 27.9 |  | 71.8 |
Gross Amounts Offset in the Statement of Financial Position | 0 |  | 0 |
Net Amounts of Assets Presented in the Statement of Financial Position | 27.9 |  | 71.8 |
Gross Amounts Not Offset in the Statement of Financial Position | (27.9) |  | (71.8) |
Net Derivative Position - Assets | 0 |  | 0 |
Gross Amounts of Recognized Liabilities | (41.9) |  | (103.4) |
Gross Amounts Offset in the Statement of Financial Position-Liabilities | 0 |  | 0 |
Net Amounts of Liabilities Presented in the Statement of Financial Position | (41.9) |  | (103.4) |
Gross Amounts Not Offset in the Statement of Financial Position- Liabilities | 27.9 |  | 71.8 |
Net Derivative Position-Liabilities | (14.0) |  | (31.6) |
Counterparty B [Member] |  |  |  |
Offsetting Assets and Liabilities [Line Items] |  |  |  |
Gross Amounts of Recognized Assets | 0.2 |  | 0.9 |
Gross Amounts Offset in the Statement of Financial Position | 0 |  | 0 |
Net Amounts of Assets Presented in the Statement of Financial Position | 0.2 |  | 0.9 |
Gross Amounts Not Offset in the Statement of Financial Position | (9.5) |  | (0.9) |
Net Derivative Position - Assets | (9.3) |  | 0 |
Gross Amounts of Recognized Liabilities | (9.5) |  | (10.8) |
Gross Amounts Offset in the Statement of Financial Position-Liabilities | 0 |  | 0 |
Net Amounts of Liabilities Presented in the Statement of Financial Position | (9.5) |  | (10.8) |
Gross Amounts Not Offset in the Statement of Financial Position- Liabilities | 9.5 |  | 0.9 |
Net Derivative Position-Liabilities | 0 |  | (9.9) |
Counterparty Other [Member] |  |  |  |
Offsetting Assets and Liabilities [Line Items] |  |  |  |
Gross Amounts of Recognized Assets | 45.4 | [1] | 75.5 | [1]
Gross Amounts Offset in the Statement of Financial Position | 0 | [1] | 0 | [1]
Net Amounts of Assets Presented in the Statement of Financial Position | 45.4 | [1] | 75.5 | [1]
Gross Amounts Not Offset in the Statement of Financial Position | 0 | [1] | 0 | [1]
Net Derivative Position - Assets | 45.4 | [1] | 75.5 | [1]
Gross Amounts of Recognized Liabilities | (1.1) | [1] | (1.3) | [1]
Gross Amounts Offset in the Statement of Financial Position-Liabilities | 0 | [1] | 0 | [1]
Net Amounts of Liabilities Presented in the Statement of Financial Position | (1.1) | [1] | (1.3) | [1]
Gross Amounts Not Offset in the Statement of Financial Position- Liabilities | 0 | [1] | 0 | [1]
Net Derivative Position-Liabilities | $ (1.1) | [1] | $ (1.3) | [1]
[1] | Amounts in 'Other' include physical positions with counterparties that are part of NiSource's natural gas marketing business as well as fixed-to-variable interest rate swap agreements entered into by NiSource.

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