Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2023
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation TEC is a wholly owned subsidiary of TECO Energy, which is an indirect, wholly owned subsidiary of Emera. TEC is comprised of the electric division, referred to as Tampa Electric, and prior to January 1, 2023, the natural gas division, referred to as PGS. See "Separation of PGS from TEC" below for further information. In the opinion of management, the unaudited consolidated condensed financial statements include all adjustments that are of a recurring nature and necessary to state fairly the financial position of TEC as of September 30, 2023 and December 31, 2022, and the results of operations and cash flows for the periods ended September 30, 2023 and 2022. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results that can be expected for the entire fiscal year ending December 31, 2023. The use of estimates is inherent in the preparation of financial statements in accordance with U.S. GAAP. Actual results could differ from these estimates. The year-end Consolidated Condensed Balance Sheet was derived from audited financial statements; however, this quarterly report on Form 10-Q does not include all year-end disclosures required for an annual report on Form 10-K by U.S. GAAP.
Separation of PGS from TEC	Separation of PGS from TEC PGS became an operating division of TEC in 1997 when TECO Energy purchased PGS and merged that corporation into TEC. Since then, PGS has operated as a stand-alone regulated utility, including having its own tariffs and its own books and records. On January 1, 2023, TEC transferred the assets and liabilities of its PGS division into a separate corporation called Peoples Gas System, Inc. pursuant to a Contribution Agreement. This new corporation is a wholly owned subsidiary of a newly formed gas operations holding company, TECO Gas Operations, Inc., a wholly owned subsidiary of TECO Energy. On January 1, 2023, the assets, liabilities, and equity that had been recorded in the books of PGS were transferred from TEC to the newly formed company at book value in a tax-free transaction. PGS issued 100 shares of common stock to TEC related to the transfer, which were subsequently distributed to TECO Energy, Inc. and then contributed to TECO Gas Operations, Inc. As a result, from and after January 1, 2023, the PGS division is no longer operated by TEC. This is a transaction between entities under common control; therefore, TEC did not recognize a gain or loss on the transaction. TEC is not required to recast its prior period financial statements and disclosures to exclude PGS prior to January 1, 2023. The TEC consolidated condensed statement of cash flows for the nine months ended September 30, 2023 does not include the non-cash impact of separating the PGS assets, liabilities and equity from TEC on January 1, 2023 and excludes PGS’s opening cash balance. The impact of the separation of PGS from TEC on the consolidated condensed statements of capital for the nine months ended September 30, 2023 was $992 million, which represents the net assets of PGS transferred as of January 1, 2023. TEC recorded $121 million to retained earnings, which was the retained earnings of PGS as of January 1, 2023, and the remainder of $871 million was recorded to additional paid in capital, which is presented with common stock. Included in the liabilities transferred was PGS’s allocation of outstanding unsecured notes and outstanding short-term borrowings issued by TEC. The obligations related to these combined borrowings are reflected in a loan agreement between TEC and PGS. The initial obligation of PGS under the loan agreement at January 1, 2023 was a term loan in the principal amount of $670 million and a revolving loan in the principal amount of $66 million. The maturity date for both is December 29, 2023. PGS intends to access the third-party lending market during 2023 but cannot predict when during the year that it will do so. To assist its affiliate and to facilitate an orderly transfer of its gas assets, Tampa Electric will continue to be responsible for providing capital as needed to PGS under a loan agreement. See Note 12 for further information regarding TEC's related party transactions with PGS. For the stand alone PGS balance sheet as of December 31, 2022, see Note 1 of TEC’s Annual Report on Form 10-K for the year ended December 31, 2022.
Receivables and Allowance for Credit Losses	Receivables and Allowance for Credit Losses Receivables on the Consolidated Condensed Balance Sheets include receivables from contracts with customers, which consist of services to residential, commercial, industrial and other customers, totaling $362 million and $295 million as of September 30, 2023 and December 31, 2022, respectively. An allowance for credit losses is established based on TEC’s collection experience and reasonable and supportable forecasts that affect the collectibility of the reported amount. Circumstances that could affect TEC’s estimates of credit losses include, but are not limited to, customer credit issues, generating fuel prices, customer deposits and general economic conditions. Accounts are reserved in the allowance or written off once they are deemed to be uncollectible. As of September 30, 2023 and December 31, 2022, unbilled revenues of $81 million and $82 million, respectively, are included in the “Receivables” line item on the Consolidated Condensed Balance Sheets.
Accounting for Franchise Fees and Gross Receipts	Accounting for Franchise Fees and Gross Receipts TEC is allowed to recover certain costs from customers on a dollar-for-dollar basis through rates approved by the FPSC. The amounts included in customers’ bills for franchise fees and gross receipt taxes are included as revenues on the Consolidated Condensed Statements of Income. Franchise fees and gross receipt taxes payable by TEC are included as an expense on the Consolidated Condensed Statements of Income in “Taxes, other than income”. These amounts totaled $43 million and $41 million for the three months ended September 30, 2023 and 2022, respectively, and totaled $106 million and $110 million for the nine months ended September 30, 2023 and 2022, respectively.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2023

Principles of Consolidation and Basis of Presentation

TEC is a wholly owned subsidiary of TECO Energy, which is an indirect, wholly owned subsidiary of Emera. TEC is comprised of the electric division, referred to as Tampa Electric, and prior to January 1, 2023, the natural gas division, referred to as PGS. See "Separation of PGS from TEC" below for further information.

In the opinion of management, the unaudited consolidated condensed financial statements include all adjustments that are of a recurring nature and necessary to state fairly the financial position of TEC as of September 30, 2023 and December 31, 2022, and the results of operations and cash flows for the periods ended September 30, 2023 and 2022. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results that can be expected for the entire fiscal year ending December 31, 2023.

The use of estimates is inherent in the preparation of financial statements in accordance with U.S. GAAP. Actual results could differ from these estimates. The year-end Consolidated Condensed Balance Sheet was derived from audited financial statements; however, this quarterly report on Form 10-Q does not include all year-end disclosures required for an annual report on Form 10-K by U.S. GAAP.

Separation of PGS from TEC

PGS became an operating division of TEC in 1997 when TECO Energy purchased PGS and merged that corporation into TEC. Since then, PGS has operated as a stand-alone regulated utility, including having its own tariffs and its own books and records.

On January 1, 2023, TEC transferred the assets and liabilities of its PGS division into a separate corporation called Peoples Gas System, Inc. pursuant to a Contribution Agreement. This new corporation is a wholly owned subsidiary of a newly formed gas operations holding company, TECO Gas Operations, Inc., a wholly owned subsidiary of TECO Energy. On January 1, 2023, the assets, liabilities, and equity that had been recorded in the books of PGS were transferred from TEC to the newly formed company at book value in a tax-free transaction. PGS issued 100 shares of common stock to TEC related to the transfer, which were subsequently distributed to TECO Energy, Inc. and then contributed to TECO Gas Operations, Inc. As a result, from and after January 1, 2023, the PGS division is no longer operated by TEC. This is a transaction between entities under common control; therefore, TEC did not recognize a gain or loss on the transaction. TEC is not required to recast its prior period financial statements and disclosures to exclude PGS prior to January 1, 2023. The TEC consolidated condensed statement of cash flows for the nine months ended September 30, 2023 does not include the non-cash impact of separating the PGS assets, liabilities and equity from TEC on January 1, 2023 and excludes PGS’s opening cash balance. The impact of the separation of PGS from TEC on the consolidated condensed statements of capital for the nine months ended September 30, 2023 was $992 million, which represents the net assets of PGS transferred as of January 1, 2023. TEC recorded $121 million to retained earnings, which was the retained earnings of PGS as of January 1, 2023, and the remainder of $871 million was recorded to additional paid in capital, which is presented with common stock.

Included in the liabilities transferred was PGS’s allocation of outstanding unsecured notes and outstanding short-term borrowings issued by TEC. The obligations related to these combined borrowings are reflected in a loan agreement between TEC and PGS. The initial obligation of PGS under the loan agreement at January 1, 2023 was a term loan in the principal amount of $670 million and a revolving loan in the principal amount of $66 million. The maturity date for both is December 29, 2023. PGS intends to access the third-party lending market during 2023 but cannot predict when during the year that it will do so. To assist its affiliate and to facilitate an orderly transfer of its gas assets, Tampa Electric will continue to be responsible for providing capital as needed to PGS under a loan agreement. See Note 12 for further information regarding TEC's related party transactions with PGS.

For the stand alone PGS balance sheet as of December 31, 2022, see Note 1 of TEC’s Annual Report on Form 10-K for the year ended December 31, 2022.

Receivables and Allowance for Credit Losses

Receivables on the Consolidated Condensed Balance Sheets include receivables from contracts with customers, which consist of services to residential, commercial, industrial and other customers, totaling $362 million and $295 million as of September 30, 2023 and December 31, 2022, respectively. An allowance for credit losses is established based on TEC’s collection experience and reasonable and supportable forecasts that affect the collectibility of the reported amount. Circumstances that could affect TEC’s

estimates of credit losses include, but are not limited to, customer credit issues, generating fuel prices, customer deposits and general economic conditions. Accounts are reserved in the allowance or written off once they are deemed to be uncollectible.

As of September 30, 2023 and December 31, 2022, unbilled revenues of $81 million and $82 million, respectively, are included in the “Receivables” line item on the Consolidated Condensed Balance Sheets.

Accounting for Franchise Fees and Gross Receipts

TEC is allowed to recover certain costs from customers on a dollar-for-dollar basis through rates approved by the FPSC. The amounts included in customers’ bills for franchise fees and gross receipt taxes are included as revenues on the Consolidated Condensed Statements of Income. Franchise fees and gross receipt taxes payable by TEC are included as an expense on the Consolidated Condensed Statements of Income in “Taxes, other than income”. These amounts totaled $43 million and $41 million for the three months ended September 30, 2023 and 2022, respectively, and totaled $106 million and $110 million for the nine months ended September 30, 2023 and 2022, respectively.