|
Transfers Of Financial Assets (Narrative) (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 6 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Dec. 31, 2012
|
Jun. 30, 2013
Columbia Gas Of Ohio Receivables Corporation [Member]
|
Jun. 30, 2013
Columbia Gas Of Pennsylvania Receivables Corporation [Member]
|
Jun. 30, 2013
NIPSCO Accounts Receivable Corporation [Member]
|
Jun. 30, 2013
Maximum [Member]
Accounts Receivable Program [Member]
|
Oct. 19, 2012
Maximum [Member]
Columbia Gas Of Ohio Receivables Corporation [Member]
|
Mar. 15, 2010
Maximum [Member]
Columbia Gas Of Pennsylvania Receivables Corporation [Member]
|
Aug. 29, 2012
Maximum [Member]
NIPSCO Accounts Receivable Corporation [Member]
|
|
| Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] | ||||||||||||
| Accounts receivable securitization facility borrowings | $ 260.1 | $ 260.1 | $ 233.3 | $ 515.0 | ||||||||
| Trade receivables, seasonal program maximum | 240 | 75 | 200 | |||||||||
| Net receivables transferred | 260.1 | 260.1 | 233.3 | 125.1 | 10.0 | 125.0 | ||||||
| Securitization transaction fees | $ 0.6 | $ 0.9 | $ 1.5 | $ 2.0 | ||||||||