Short-Term Borrowings	9 Months Ended
Short-Term Borrowings	Sep. 30, 2023
Short-Term Debt [Abstract]
Short-Term Borrowings	We generate short-term borrowings from our revolving credit facility, commercial paper program, accounts receivable transfer programs, and term credit agreement. Each of these borrowing sources is described further below. Revolving Credit Facility. We maintain a revolving credit facility to fund ongoing working capital requirements, including the provision of liquidity support for our commercial paper program, provide for issuance of letters of credit and also for general corporate purposes. Our revolving credit facility has a program limit of $1.85 billion and is comprised of a syndicate of banks. We had no outstanding borrowings under this facility as of September 30, 2023 and December 31, 2022. Commercial Paper Program. Our commercial paper program has a program limit of up to $1.5 billion. We had $935.0 million and $415.0 million of commercial paper outstanding with weighted-average interest rates of 5.58% and 4.60% as of September 30, 2023 and December 31, 2022, respectively. Accounts Receivable Transfer Programs. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania each maintain a receivables agreement whereby they transfer their customer accounts receivables to third-party financial institutions through wholly owned and consolidated special purpose entities. The three agreements expire between May 2024 and October 2024 and may be further extended if mutually agreed to by the parties thereto. All receivables transferred to third parties are valued at face value, which approximates fair value due to their short-term nature. The amount of the undivided percentage ownership interest in the accounts receivables transferred is determined in part by required loss reserves under the agreements. Transfers of accounts receivable are accounted for as secured borrowings resulting in the recognition of short-term borrowings on the Condensed Consolidated Balance Sheets (unaudited). As of September 30, 2023, the maximum amount of debt that could be borrowed related to our accounts receivable programs was $295.6 million. We had $285.0 million and $347.2 million of short-term borrowings related to the securitization transactions as of September 30, 2023 and December 31, 2022, respectively. For the nine months ended September 30, 2023, $62.2 million was recorded as cash flows used for financing activities related to the change in short-term borrowings due to securitization transactions. For the nine months ended September 30, 2022, $318.2 million was recorded as cash flows from financing activities related to the change in short-term borrowings due to securitization transactions. Fees associated with the securitization transactions were $0.5 million and $0.7 million for the three months ended September 30, 2023 and 2022, respectively and $2.1 million and $1.7 million for the nine months ended September 30, 2023 and 2022, respectively. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania remain responsible for collecting on the receivables securitized, and the receivables cannot be transferred to another party. Term Credit Agreement. On December 20, 2022, we entered into a $1.0 billion term credit agreement with a syndicate of banks. On October 5, 2023, we entered into an amendment with the syndicate of banks to, among other things, extend the maturity date of the agreement from December 19, 2023 to March 15, 2024. With the amendment, we triggered extinguishment accounting and will record an immaterial loss on extinguishment of debt in the fourth quarter of 2023. Interest charged on the borrowings depends on the variable rate structure elected at the time of each borrowing. The available variable rate structures from which we can choose are defined in the agreement. Under the agreement, we borrowed $1.0 billion on December 20, 2022 with an interest rate of SOFR plus 105 basis points. We had $1.0 billion outstanding under this agreement with interest rates of 6.37% and 5.37% as of September 30, 2023 and December 31, 2022, respectively. Items listed above, excluding the term credit agreement, are presented net in the Condensed Statements of Consolidated Cash Flows (unaudited) as their maturities are less than 90 days.