Tampa Electric 10-Q 12 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 10, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Registrant Name	TAMPA ELECTRIC COMPANY
Entity Interactive Data Current	Yes
Entity File Number	1-5007
Entity Address, Address Line One	TECO Plaza
Entity Address, Address Line Two	702 N. Franklin Street
Entity Address, City or Town	Tampa
Entity Address, State or Province	FL
Entity Tax Identification Number	59-0475140
Entity Incorporation, State or Country Code	FL
Entity Address, Postal Zip Code	33602
City Area Code	813
Local Phone Number	228-1111
Document Quarterly Report	true
Document Transition Report	false
Entity Central Index Key	0000096271
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		10

Consolidated Condensed Balance

Consolidated Condensed Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Property, plant and equipment
Utility plant, at original costs	$ 14,053	$ 13,818
Accumulated depreciation	(3,792)	(3,712)
Utility plant, net	10,261	10,106
Other property	14	14
Total property, plant and equipment, net	10,275	10,120
Current assets
Cash and cash equivalents	14	10
Receivables, less allowance for credit losses of $7 and $7 at March 31, 2021 and December 31, 2020, respectively	225	219
Due from affiliates	8	11
Inventories, at average cost
Regulatory assets	64	79
Prepayments and other current assets	15	10
Total current assets	456	462
Deferred debits
Regulatory assets	416	406
Other	61	60
Total deferred debits	477	466
Total assets	11,208	11,048
Capitalization
Common stock	4,045	3,890
Accumulated other comprehensive loss	(1)	(1)
Retained earnings	331	327
Total capital	4,375	4,216
Long-term debt	3,386	2,594
Total capitalization	7,761	6,810
Current liabilities
Long-term debt due within one year	278	278
Notes payable	10	775
Accounts payable	247	321
Due to affiliates	45	46
Customer deposits	130	130
Regulatory liabilities	62	67
Accrued interest	45	13
Accrued taxes	40	22
Other	48	57
Total current liabilities	905	1,709
Long-term liabilities
Deferred income taxes	789	783
Regulatory liabilities	1,190	1,194
Investment tax credits	237	216
Deferred credits and other liabilities	326	336
Total long-term liabilities	2,542	2,529
Commitments and Contingencies (see Note 8)
Total liabilities and capitalization	11,208	11,048
Fuel [Member]
Inventories, at average cost
Utility inventories	22	26
Materials and Supplies [Member]
Inventories, at average cost
Utility inventories	108	107
Electric [Member]
Property, plant and equipment
Utility plant, at original costs	11,646	11,486
Gas [Member]
Property, plant and equipment
Utility plant, at original costs	$ 2,407	$ 2,332

Consolidated Condensed Balanc_2

Consolidated Condensed Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Allowance for credit losses	$ 7	$ 7

Consolidated Condensed Statemen

Consolidated Condensed Statements of Income and Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues
Electric	$ 446	$ 420
Gas	153	127
Total revenues	599	547
Expenses
Fuel	109	101
Purchased power	18	2
Cost of natural gas sold	50	42
Operations and maintenance	128	134
Depreciation and amortization	106	97
Taxes, other than income	54	51
Total expenses	465	427
Income from operations	134	120
Other income
Allowance for equity funds used during construction	10	6
Other income, net	1	1
Total other income	11	7
Interest charges
Interest expense	38	37
Allowance for borrowed funds used during construction	(5)	(3)
Total interest charges	33	34
Income before provision for income taxes	112	93
Provision for income taxes	20	16
Net income	92	77
Comprehensive income	$ 92	$ 77

Consolidated Condensed Statem_2

Consolidated Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 92	$ 77
Adjustments to reconcile net income to cash from operating activities:
Depreciation and amortization	106	97
Deferred income taxes and investment tax credits	22	31
Allowance for equity funds used during construction	(10)	(6)
Deferred recovery clauses	(3)	38
Receivables, less allowance for credit losses	(3)	(7)
Inventories	3	9
Taxes accrued	15	1
Interest accrued	32	31
Accounts payable	(62)	(52)
Regulatory assets and liabilities	0	(12)
Other	(12)	(15)
Cash flows from operating activities	180	192
Cash flows used in investing activities
Capital expenditures	(270)	(324)
Net proceeds from sale of assets	0	6
Cash flows used in investing activities	(270)	(318)
Cash flows from financing activities
Equity contributions from Parent	155	145
Proceeds from long-term debt issuance	792	0
Net increase (decrease) in short-term debt (maturities of 90 days or less)	(465)	(244)
Proceeds from other short-term debt (maturities over 90 days)	0	300
Repayment of other short-term debt (maturities over 90 days)	(300)	0
Dividends to Parent	(88)	(73)
Cash flows from financing activities	94	128
Net increase in cash and cash equivalents	4	2
Cash and cash equivalents at beginning of period	10	14
Cash and cash equivalents at end of period	14	16
Supplemental disclosure of non-cash activities
Change in accrued capital expenditures	$ (12)	$ (2)

Consolidated Condensed Statem_3

Consolidated Condensed Statements of Capital (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Beginning balance	$ 4,216	$ 3,695
Net income	92	77
Equity contributions from Parent	155	145
Dividends to Parent	(88)	(73)
Other		1
Ending balance	4,375	3,845
Common Stock [Member]
Beginning balance	$ 3,890	$ 3,385
Beginning balance	10	10
Equity contributions from Parent	$ 155	$ 145
Ending balance	$ 4,045	$ 3,530
Ending balance	10	10
Retained Earnings [Member]
Beginning balance	$ 327	$ 311
Net income	92	77
Dividends to Parent	(88)	(73)
Other		1
Ending balance	331	316
Accumulated Other Comprehensive Loss [Member]
Beginning balance	(1)	(1)
Ending balance	$ (1)	$ (1)

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies See TEC’s Annual Report on Form 10-K for the year ended December 31, 2020 for a complete discussion of accounting policies. The significant accounting policies for TEC include: 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 the natural gas division, referred to as PGS. Intercompany balances and transactions within the divisions have been eliminated in consolidation. 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 March 31, 2021 and December 31, 2020, and the results of operations and cash flows for the periods ended March 31, 2021 and 2020. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results that can be expected for the entire fiscal year ending December 31, 2021. 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. Since 2020, the outbreak of the novel strain of coronavirus, specifically identified as COVID-19, has resulted in governments worldwide enacting emergency measures to combat the spread of the virus. While management considered the impact of the COVID-19 pandemic in TEC’s estimates and results, the financial statements as of March 31, 2021 and December 31, 2020 and for the three months ended March 31, 2021 and 2020 were not materially impacted by the COVID-19 pandemic. However, it is not possible to reliably estimate the length and severity of the COVID-19 pandemic and the impact on the financial results and condition of TEC in future periods. Receivables and Allowance for Credit Losses Receivables from contracts with customers, which consist of services to residential, commercial, industrial and other customers, were $220 million and $214 million as of March 31, 2021 and December 31, 2020, 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 Tampa Electric’s and PGS’s estimates of credit losses include, but are not limited to, customer credit issues, generating fuel prices, customer deposits and general economic conditions, including the impacts of the COVID-19 pandemic. Accounts are reserved in the allowance or written off once they are deemed to be uncollectible. As of March 31, 2021 and December 31, 2020, unbilled revenues of $74 million and $73 million, respectively, are included in the “Receivables” line item on the Consolidated Condensed Balance Sheets. Accounting for Franchise Fees and Gross Receipts Tampa Electric and PGS are 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 Tampa Electric and PGS are included as an expense on the Consolidated Condensed Statements of Income in “Taxes, other than income”. These amounts totaled $29 million and $27 million for the three months ended March 31, 2021 and 2020, respectively.

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2021
Accounting Changes And Error Corrections [Abstract]
New Accounting Pronouncements	2. New Accounting Pronouncements TEC considers the applicability and impact of all ASUs issued by the FASB. The ASUs that have been issued, but that are not yet effective, are consistent with those disclosed in TEC’s Annual Report on Form 10-K for the year ended December 31, 2020 .

Regulatory

Regulatory	3 Months Ended
	Mar. 31, 2021
Regulated Operations [Abstract]
Regulatory	3. Regulatory Tampa Electric Base Rates On September 27, 2017, Tampa Electric filed with the FPSC an amended and restated settlement agreement that replaced the existing 2013 base rate settlement agreement and extended it another four years through December 31, 2021. The FPSC approved the agreement on November 6, 2017. The amended agreement provides for SoBRAs for TEC’s investments in up to 600 MW of cost-effective solar generation. Tampa Electric has invested approximately $850 million during 2017 through 2021 related to 600 MW of solar projects recoverable under the SoBRAs, and AFUDC was accrued during construction. On December 12, 2017, TEC filed its first petition regarding the SoBRAs along with supporting tariffs demonstrating the cost-effectiveness of the September 1, 2018 tranche representing 145 MW and $24 million annually in estimated revenue requirements. The FPSC approved the tariffs on the first SoBRA filing on May 8, 2018 and TEC began receiving these revenues in September 2018 requirements. The FPSC approved the tariffs on the second SoBRA filing on October 29, 2018 and TEC began receiving these revenues in January 2019. On June 28, 2019, TEC filed its third SoBRA petition along with supporting tariffs demonstrating the cost-effectiveness of the January 1, 2020 tranche representing 149 MW and $26 million annually in estimated revenue requirements. The FPSC approved the tariffs on this SoBRA filing, including an adjustment to reflect the reduction in the state corporate income tax discussed below, on December 10, 2019 and TEC began receiving these revenues in January 2020. On July 31, 2020, TEC filed its fourth and final SoBRA petition along with supporting tariffs demonstrating the cost-effectiveness of the January 1, 2021 tranche representing 46 MW and $8 million annually in estimated revenues. The FPSC approved the tariffs on this SoBRA filing on November 3, 2020 and TEC began receiving these revenues in January 2021. The true-up filing for SoBRA tranche 1 and 2 revenue requirement estimates that were included in base rates as of September 2018 and January 2019, respectively, was submitted on April 30, 2020, and the FPSC approved the amount on August 18, 2020. The $5 million true-up was returned to customers in 2020. The true-ups for SoBRA tranches 3 and 4 will be filed in 2021 and 2022, respectively. On April 9, 2021, Tampa Electric requested a base rate increase, reflecting increased revenue requirements of $295 million, effective January 1, 2022. Tampa Electric’s proposed 2022 rates include recovery for the costs of the first phase of the Big Bend modernization project, 225 MW of utility-scale solar projects, the AMI investment, and accelerated recovery of the remaining net book value of retiring coal and other assets. Tampa Electric also requested approval for Generation Base Rate Adjustments for 2023 and 2024 that total approximately $130 million to recover the remaining investments in the Big Bend modernization project and additional utility-scale solar projects in subsequent years. A decision by the FPSC is expected by the end of 2021. Tampa Electric Big Bend Modernization Project Tampa Electric expects to invest approximately $850 million during 2018 through 2023 to modernize the Big Bend Power Station, of which approximately $574 million has been invested through March 31, 2021. The Big Bend modernization project will repower Big Bend Unit 1 with natural gas combined-cycle technology and eliminate coal as this unit’s fuel. As part of the Big Bend modernization project, on June 1, 2020, Tampa Electric retired the Unit 1 components that will not be used in the modernized plant. At March 31, 2021 and December 31, 2020, Tampa Electric’s balance sheet included $200 million In accordance with Tampa Electric’s 2017 settlement agreement, Tampa Electric was not required to request an asset recovery schedule for retired assets until the next depreciation study. On December 30, 2020, Tampa Electric filed a depreciation and dismantlement study and request for capital recovery schedule with the FPSC. Tampa Electric plans to retire Big Bend Unit 3 in 2023 as it is in the best interest of customers from economic, environmental risk and operational perspectives. Similar to the retirement plan for Unit 1 and Unit 2, Tampa Electric will continue to account for its existing investment in Unit 3 in electric utility plant and depreciate the assets using the current depreciation rates until the FPSC approves a new Tampa Electric depreciation and dismantlement study. Tampa Electric Storm Protection Cost Recovery Clause and Settlement Agreement On October 3, 2019, the FPSC issued a rule to implement a Storm Protection Plan (SPP) Cost Recovery Clause. This new clause provides a process for Florida investor-owned utilities, including Tampa Electric, to recover transmission and distribution storm hardening costs for incremental activities not already included in base rates. Tampa Electric submitted its storm protection plan with the FPSC on April 10, 2020. On April 27, 2020, Tampa Electric submitted a settlement agreement with the FPSC which specified a $15 million base rate reduction for SPP program costs previously recovered in base rates beginning January 1, 2021. On June 9, 2020, the FPSC approved this settlement agreement. On August 3, 2020, Tampa Electric submitted another settlement agreement to the FPSC for approval, including cost recovery of approximately $39 million in proposed storm protection project costs for 2020 and 2021. This cost recovery includes the $15 million of costs removed from base rates. This settlement agreement was approved on August 10, 2020, and Tampa Electric’s cost recovery began in January 2021. The current approved plan will apply for the years 2020, 2021 and 2022, and Tampa Electric will file a new plan in 2022 to determine cost recovery in 2023, 2024, and 2025. The June 9, 2020 settlement agreement approved by the FPSC described above also included approval of Tampa Electric’s petition to eliminate its $16 million accumulated amortization reserve surplus for intangible software assets through a credit to amortization expense in 2020. PGS Base Rates PGS’s 2020 base rates were established in 2009. In accordance with its 2017 settlement agreement, PGS had an allowed regulatory ROE range of 9.25% to 11.75%, reduced annual depreciation expense by $16 million, and accelerated the amortization of the regulatory asset associated with environmental remediation costs by $32 million over the period 2016 through 2020 On June 8, 2020, PGS filed a petition for an increase in rates and service charges effective January 2021. On November 19, 2020, the FPSC approved a settlement agreement filed by PGS. The settlement agreement allows for an increase in base rates by $58 million annually effective January 2021, which is a $34 million increase in revenue and $24 million increase of revenues previously recovered through the cast iron and bare steel replacement rider. This settlement agreement includes an allowed regulatory ROE range of 8.90% to 11.00% with a 9.90% midpoint. It provides PGS the ability to reverse a total of $34 million of accumulated depreciation through 2023 and sets new depreciation rates effective January 1, 2021 that are consistent with PGS’s current overall average depreciation rate. Under the agreement, base rates are frozen from January 1, 2021 to December 31, 2023, unless its earned ROE were to fall below 8.90% before that time with an allowed equity in the capital structure of 54.7% from investor sources of capital. The settlement agreement further addresses tax rate changes. The agreement contains a provision whereby PGS agrees to quantify the future impact of a decrease in tax rates on net operating income through a reduction in base revenues within 120 days of when such tax change becomes law. If on the contrary, tax legislation results in a tax rate increase, PGS can establish a regulatory asset to neutralize the impact of the increase in income tax rate to be addressed in a future proceeding and with recovery beginning no sooner than January 2024 . Regulatory Assets and Liabilities Details of the regulatory assets and liabilities are presented in the following table: Regulatory Assets and Liabilities (millions) March 31, 2021 December 31, 2020 Regulatory assets: Regulatory tax asset (1) $ 96 $ 90 Cost-recovery clauses (2) 35 38 Environmental remediation (3) 23 22 Postretirement benefits (4) 303 309 Asset retirement obligation (5) 12 13 Other 11 13 Total regulatory assets 480 485 Less: Current portion 64 79 Long-term regulatory assets $ 416 $ 406 Regulatory liabilities: Regulatory tax liability (6) $ 691 $ 691 Cost-recovery clauses (2) 17 23 Accumulated reserve - cost of removal (7) 494 498 Storm reserve (8) 48 48 Other 2 1 Total regulatory liabilities 1,252 1,261 Less: Current portion 62 67 Long-term regulatory liabilities $ 1,190 $ 1,194 The regulatory tax asset is primarily associated with the depreciation and recovery of AFUDC-equity. This asset does not earn a return but rather is included in the capital structure, which is used in the calculation of the weighted cost of capital used to determine revenue requirements. It will be recovered over the expected life of the related assets. The regulatory tax asset balance reflects the impact of the federal tax rate reduction. (2) These assets and liabilities are related to FPSC clauses and riders. They are recovered or refunded through cost-recovery mechanisms approved by the FPSC on a dollar-for-dollar basis in a subsequent period. (3) This asset is related to costs associated with environmental remediation primarily at MGP sites. The balance is included in rate base, partially offsetting the related liability, and earns a rate of return as permitted by the FPSC. The timing of recovery is based on a settlement agreement approved by the FPSC. (4) This asset is related to the deferred costs of postretirement benefits and it is amortized over the remaining service life of plan participants. Deferred costs of postretirement benefits that are included in expense are recognized as cost of service for rate-making purposes as permitted by the FPSC. (5) This asset is related to costs associated with an asset retirement obligation, which is a legal obligation for the future retirement of certain tangible, long-lived assets. This regulatory asset does not earn a return because it is offset with related assets and liabilities within rate base. It is recovered and removed as the obligation is settled and removed as the activities for the retirement of the related assets have been completed. (6) The regulatory tax liability is primarily related to the revaluation of TEC’s deferred income tax balances recorded on December 31, 2017 at the lower income tax rate due to U.S. tax reform. The liability related to the revaluation of the deferred income tax balances is amortized and returned to customers through rate reductions or other revenue offsets based on IRS regulations and the settlement agreement for tax reform benefits approved by the FPSC. (7) This item represents the non-ARO cost of removal in the accumulated reserve for depreciation. AROs are costs for legally required removal of property, plant and equipment. Non-ARO cost of removal represents estimated funds received from customers through depreciation rates to cover future non-legally required cost of removal of property, plant and equipment, net of salvage value upon retirement, which reduces rate base for ratemaking purposes. This liability is reduced as costs of removal are incurred. (8) As a result of Tampa Electric’s 2013 rate case settlement, in the event of a named storm that results in damage to its system, Tampa Electric can petition the FPSC to seek recovery of those costs over a 12-month period or longer as determined by the FPSC, as well as replenish its reserve to $56 million, the level of the reserve as of October 31, 2013. In 2019, Tampa Electric incurred storm restoration preparation costs for Hurricane Dorian of approximately $8 million, which was charged to the storm reserve regulatory liability.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	4. Income Taxes CARES Act On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security (CARES) Act was signed into law. The CARES Act includes several business provisions including deferral in employer payroll taxes and an employee retention payroll tax credit. On December 27, 2020, the Consolidated Appropriations Act, 2021 (the 2021 Act) was signed into law. The 2021 Act provides for modifications and expansion of the employee retention payroll tax credit enacted under the CARES Act. These Acts did not have a material impact to TEC’s financial statements. American Rescue Plan Act of 2021 On March 11, 2021, the American Rescue Plan Act of 2021 (the Act) was signed into law. The Act includes an extension of the employee retention credit through December 31, 2021. The Act did not have a material impact to TEC’s financial statements. Income Tax Expense TEC is included in a consolidated U.S. federal income tax return with EUSHI and its subsidiaries. TEC’s income tax expense is based upon a separate return method, modified for the benefits-for-loss allocation in accordance with respective tax sharing agreements with TECO Energy and EUSHI. To the extent that TEC’s cash tax positions are settled differently than the amount reported as realized under the tax sharing agreement, the difference is reflected in common stock. TEC’s effective tax rates for the three months ended March 31, 2021 and 2020 were 17.9% and 17.2%, respectively. The March 31, 2021 and 2020 effective tax rates are an estimate of the annual effective income tax rate. TEC’s effective tax rate for the three months ended March 31, 2021 and 2020 differed from the statutory rate principally due to the amortization of the regulatory tax liability resulting from tax reform. See Note 3 Unrecognized Tax Benefits As of March 31, 2021 and December 31, 2020, the amount of unrecognized tax benefits was $5 million and $9 million, respectively, all of which was recorded as a reduction of deferred income tax assets for tax credit carryforwards. TEC’s unrecognized federal tax benefits decreased in the first quarter of 2021 by approximately $5 million due to the settlement of its 2016 federal IRS Appeals R&D tax credits issue. TEC had $5 million and $9 million of unrecognized tax benefits at March 31, 2021 and December 31, 2020, that, if recognized, would reduce TEC’s effective tax rate.

Employee Postretirement Benefit

Employee Postretirement Benefits	3 Months Ended
	Mar. 31, 2021
Compensation And Retirement Disclosure [Abstract]
Employee Postretirement Benefits	5. Employee Postretirement Benefits TEC is a participant in the comprehensive retirement plans of TECO Energy. The following table presents detail related to TECO Energy’s periodic benefit cost for pension and other postretirement benefits. Amounts disclosed for TECO Energy’s pension benefits include the amounts related to its qualified pension plan and non-qualified, non-contributory SERP and Restoration Plan. TECO Energy Benefit Cost (millions) Pension Benefits Other Postretirement Benefits Three months ended March 31, 2021 2020 2021 2020 Components of net periodic benefit cost Service cost $ 5 $ 5 $ 0 $ 0 Interest cost 5 7 1 1 Expected return on assets (13 ) (13 ) 0 0 Amortization of: Actuarial loss (gain) 6 5 1 0 Net periodic benefit cost $ 3 $ 4 $ 2 $ 1 TEC’s portion of the net periodic benefit cost for the three months ended March 31, 2021 and 2020, respectively, was $3 million and $3 million for pension benefits, and $2 million and $2 million for other postretirement benefits. TEC’s portion of net periodic benefit costs for pension and other benefits is included as an expense on the Consolidated Condensed Statements of Income in “Operations & maintenance”. TECO Energy assumed a long-term EROA of 6.70% and a discount rate of 2.38% for pension benefits under its qualified pension plan for 2021. For TECO Energy’s other postretirement benefits, TECO Energy used a discount rate of 2.47% for 2021. TECO Energy made contributions of $5 million to its qualified pension plan in each of the three months ended March 31, 2021 and 2020. TEC’s portion of these contributions was $4 million in each period. TECO Energy expects to make contributions to the pension plan of $16 million for the remainder of 2021. TEC estimates its portion of the remaining 2021 contribution to be $13 million. Included in the benefit cost discussed above, for the three months ended March 31, 2021, $6 million of unamortized prior service benefits and costs and actuarial gains and losses were reclassified by TEC from regulatory assets to the Consolidated Condensed Statement of Income, compared with $4 million for the three months ended March 31, 2020.

Short-Term Debt

Short-Term Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Short-Term Debt	6. Short-Term Debt Details of TEC’s credit facilities and related borrowings are presented in the following table: March 31, 2021 December 31, 2020 Letters Letters Credit Borrowings of Credit Credit Borrowings of Credit (millions) Facilities Outstanding (1) Outstanding Facilities Outstanding (1) Outstanding 5-year facility (2) $ 800 $ 10 $ 1 $ 800 $ 345 $ 1 3-year accounts receivable facility (3) 0 0 0 150 130 0 1-year term facility (4) 0 0 0 300 300 0 Total $ 800 $ 10 $ 1 $ 1,250 $ 775 $ 1 (1) Borrowings outstanding are reported as notes payable. (2) This 5-year facility matures March 22, 2023. (3) This 3-year facility matured on March 22, 2021. (4) This 1-year term facility was terminated on March 23, 2021. At March 31, 2021, the credit facility required a commitment fee of 12.5 Accounts Receivable Facility On July 14, 2020 and October 30, 2020, TEC amended its $150 million accounts receivable collateralized borrowing facility (Loan Agreement) in order to change certain performance ratios. The amended Loan Agreement was effective as of June 30, 2020 and September 30, 2020. On March 22, 2021, this agreement matured and terminated. Non Revolving Term Loan On February 6, 2020, TEC entered into a 364-day, $300 million credit agreement with a group of banks. The credit agreement had a maturity date of February 4, 2021; contained customary representations and warranties, events of default, and financial and other covenants; and provided for interest to accrue at variable rates based on either the London interbank deposit rate, Wells Fargo Bank’s prime rate, or the federal funds rate, plus a margin. On January 29, 2021, TEC extended the maturity date of the agreement to April 29, 2021. On March 23, 2021, this loan was repaid and terminated. 5-Year Credit Facility On December 18, 2020, TEC amended and restated its bank credit facility, entering into a Sixth Amended and Restated Credit Agreement. The amendment extended the maturity date of the credit facility from March 22, 2022 to March 22, 2023 (subject to further extension with the consent of each lender); increased the amount of the commitment by the lenders to $800 million; and provided for an interest rate based on either the London interbank deposit rate, Wells Fargo Bank’s prime rate, or the federal funds rate, plus a margin; allows TEC to borrow funds on a same-day basis under a swingline loan provision, which loans mature on the fourth banking day after which any such loans are made and bear interest at an interest rate as agreed by the borrower and the relevant swingline lender prior to the making of any such loans; continues to allow TEC to request the lenders to increase their commitments under the credit facility by up to $100 million in the aggregate; includes a $80 million letter of credit facility; and made other technical changes.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	7. Long-Term Debt Fair Value of Long-Term Debt At March 31, 2021, TEC’s long-term debt, including the current portion, had a carrying amount of $3,664 million and an estimated fair market value of $4,136 million. At December 31, 2020, TEC’s total long-term debt, including the current portion, had a carrying amount of $2,872 million and an estimated fair market value of $3,597 million. The fair value of the debt securities is determined using Level 2 measurements Note 11 Tampa Electric Company 2.40% Notes due 2031 and 3.45% Notes due 2051 On March 18, 2021, TEC completed a sale of (i) $400 million aggregate principal amount of 2.40% Notes due March 15, 2031 (the 2031 Notes) and (ii) $400 million aggregate principal amount of 3.45% Notes due March 15, 2051 (the 2051 Notes, and collectively, the Notes). Until December 15, 2030, in the case of the 2031 Notes, or September 15, 2050, in the case of the 2051 Notes, TEC may redeem all or any part of such series of Notes at its option at a redemption price equal to the greater of (i) 100% of the principal amount of such series of Notes to be redeemed or (ii) the sum of the present values of the remaining payments of principal and interest on the Notes to be redeemed that would be due if the Notes matured on (a) December 15, 2030, in the case of the 2031 Notes, discounted to the redemption date on a semiannual basis at the applicable treasury rate (as defined in the Indenture), plus 15 basis points, or (b) September 15, 2050, in the case of the 2051 Notes, discounted to the redemption date on a semiannual basis at the applicable treasury rate, plus 20 basis points; in either case, the redemption price would include accrued and unpaid interest to the redemption date. At any time on or after December 15, 2030, in the case of the 2031 Notes or September 15, 2050, in the case of the 2051 Notes, TEC may, at its option, redeem such series of the Notes, in whole or in part, at 100% of the principal amount of such series of the Notes being redeemed plus accrued and unpaid interest thereon to, but excluding, the date of redemption.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Legal Contingencies From time to time, TEC and its subsidiaries are involved in various legal, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies in the ordinary course of business. Where appropriate, accruals are made in accordance with accounting standards for contingencies to provide for matters that are probable of resulting in an estimable loss. Superfund and Former Manufactured Gas Plant Sites TEC, through its Tampa Electric and PGS divisions, is a PRP for certain superfund sites and, through its PGS division, for certain former MGP sites. While the joint and several liability associated with these sites presents the potential for significant response costs, as of March 31, 2021 and December 31, 2020, TEC has estimated its ultimate financial liability to be $17 million The estimated amounts represent only the portion of the cleanup costs attributable to TEC. The estimates to perform the work are based on TEC’s experience with similar work, adjusted for site-specific conditions and agreements with the respective governmental agencies. The estimates are made in current dollars, are not discounted and do not assume any insurance recoveries. In instances where other PRPs are involved, most of those PRPs are creditworthy and are likely to continue to be creditworthy for the duration of the remediation work. However, in those instances that they are not, TEC could be liable for more than TEC’s currently assessed percentage of the remediation costs. Factors that could impact these estimates include the ability of other PRPs to pay their pro-rata portion of the cleanup costs, additional testing and investigation which could expand the scope of the cleanup activities, additional liability that might arise from the cleanup activities themselves or changes in laws or regulations that could require additional remediation. Under current regulations, these costs are recoverable through customer rates established in subsequent base rate proceedings. See Note 3 Long-Term Commitments TEC has commitments for various purchases as disclosed below, including payment obligations under contractual agreements for fuel, fuel transportation and power purchases that are recovered from customers under regulatory clauses. The following is a schedule of future payments under PPAs, minimum lease payments with non-cancelable lease terms in excess of one year, and other net purchase obligations/commitments at March 31, 2021: Long-term Demand Purchased Capital Fuel and Service Operating Side (millions) Power Transportation Projects Gas Supply Agreements Leases Management Total 2021 $ 35 $ 175 $ 300 $ 197 $ 10 $ 2 $ 3 $ 722 2022 0 233 75 42 12 3 3 368 2023 0 212 57 1 15 3 0 288 2024 0 207 0 0 15 3 0 225 2025 0 188 0 0 16 2 0 206 Thereafter 0 1,998 0 0 54 48 0 2,100 Total future minimum payments $ 35 $ 3,013 $ 432 $ 240 $ 122 $ 61 $ 6 $ 3,909 Debt Covenants TEC must meet certain financial tests, including a debt to capital ratio, as defined in the applicable debt agreements and has certain restrictive covenants in specific agreements and debt instruments. At March 31, 2021, TEC was in compliance with all required covenants.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Segment Information	9. Segment Information (millions) Tampa Tampa Electric Three months ended March 31, Electric PGS Eliminations Company 2021 Revenues - external $ 446 $ 153 $ 0 $ 599 Intracompany sales 1 2 (3 ) 0 Total revenues 447 155 (3 ) 599 Total interest charges 28 5 0 33 Net income $ 65 $ 27 $ 0 $ 92 2020 Revenues - external $ 420 $ 127 $ 0 $ 547 Intracompany sales 1 2 (3 ) 0 Total revenues 421 129 (3 ) 547 Total interest charges 30 4 0 34 Net income $ 59 $ 18 $ 0 $ 77 Total assets at March 31, 2021 $ 9,909 $ 1,968 $ (669 ) (1) $ 11,208 Total assets at December 31, 2020 $ 9,800 $ 1,901 $ (653 ) (1) $ 11,048 (1) Amounts primarily relate to consolidated deferred tax reclassifications. Deferred tax assets are reclassified and netted with deferred tax liabilities upon consolidation.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2021
Revenues [Abstract]
Revenue	10. Revenue The following disaggregates TEC’s revenue by major source: (millions) Tampa Tampa Electric Three months ended March 31, 2021 Electric PGS Eliminations Company Electric revenue Residential $ 232 $ 0 $ 0 $ 232 Commercial 126 0 0 126 Industrial 37 0 0 37 Regulatory deferrals and unbilled revenue (2 ) 0 0 (2 ) Other (1) 54 0 (1 ) 53 Total electric revenue 447 0 (1 ) 446 Gas revenue Residential 0 67 0 67 Commercial 0 53 0 53 Industrial (2) 0 6 0 6 Other (3) 0 29 (2 ) 27 Total gas revenue 0 155 (2 ) 153 Total revenue $ 447 $ 155 $ (3 ) $ 599 Three months ended March 31, 2020 Electric revenue Residential $ 205 $ 0 $ 0 $ 205 Commercial 125 0 0 125 Industrial 37 0 0 37 Regulatory deferrals and unbilled revenue (2 ) 0 0 (2 ) Other (1) 56 0 (1 ) 55 Total electric revenue 421 0 (1 ) 420 Gas revenue Residential 0 48 0 48 Commercial 0 41 0 41 Industrial (2) 0 6 0 6 Other (3) 0 34 (2 ) 32 Total gas revenue 0 129 (2 ) 127 Total revenue $ 421 $ 129 $ (3 ) $ 547 (1) Other electric revenue includes sales to public authorities, off-system sales to other utilities and various other items. (2) Industrial gas revenue includes sales to power generation customers. (3) Other gas revenue includes off-system sales to other utilities and various other items. Remaining performance obligations primarily represent lighting contracts and gas transportation contracts with fixed contract terms. As of March 31, 2021 and December 31, 2020, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $131 million and $135 million, respectively. As allowed under ASC 606, these amounts exclude contracts with an original expected length of one year or less and variable amounts for which TEC recognizes revenue at the amount to which it has the right to invoice for services performed. TEC expects to recognize revenue for the remaining performance obligations through 2033.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	11. Fair Value Measurements Items Measured at Fair Value on a Recurring Basis Accounting guidance governing fair value measurements and disclosures provides that fair value represents the amount that would be received in selling an asset or the amount that would be paid in transferring a liability in an orderly transaction between market participants. As a basis for considering assumptions that market participants would use in pricing an asset or liability, accounting guidance also establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs, such as quoted prices in active markets; Level 2: Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs for which there is little or no market data, which require the reporting entity to develop its own assumptions. There were no Level 3 assets or liabilities for the periods presented. As of March 31, 2021 and December 31, 2020, the carrying value of TEC’s short-term debt was not materially different from the fair value due to the short-term nature of the instruments and because the stated rates approximate market rates. The fair value of TEC’s short-term debt is determined using Level 2 measurements. See Note 7

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
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 the natural gas division, referred to as PGS. Intercompany balances and transactions within the divisions have been eliminated in consolidation. 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 March 31, 2021 and December 31, 2020, and the results of operations and cash flows for the periods ended March 31, 2021 and 2020. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results that can be expected for the entire fiscal year ending December 31, 2021. 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. Since 2020, the outbreak of the novel strain of coronavirus, specifically identified as COVID-19, has resulted in governments worldwide enacting emergency measures to combat the spread of the virus. While management considered the impact of the COVID-19 pandemic in TEC’s estimates and results, the financial statements as of March 31, 2021 and December 31, 2020 and for the three months ended March 31, 2021 and 2020 were not materially impacted by the COVID-19 pandemic. However, it is not possible to reliably estimate the length and severity of the COVID-19 pandemic and the impact on the financial results and condition of TEC in future periods.
Receivables and Allowance for Credit Losses	Receivables and Allowance for Credit Losses Receivables from contracts with customers, which consist of services to residential, commercial, industrial and other customers, were $220 million and $214 million as of March 31, 2021 and December 31, 2020, 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 Tampa Electric’s and PGS’s estimates of credit losses include, but are not limited to, customer credit issues, generating fuel prices, customer deposits and general economic conditions, including the impacts of the COVID-19 pandemic. Accounts are reserved in the allowance or written off once they are deemed to be uncollectible. As of March 31, 2021 and December 31, 2020, unbilled revenues of $74 million and $73 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 Tampa Electric and PGS are 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 Tampa Electric and PGS are included as an expense on the Consolidated Condensed Statements of Income in “Taxes, other than income”. These amounts totaled $29 million and $27 million for the three months ended March 31, 2021 and 2020, respectively.

Regulatory (Tables)

Regulatory (Tables)	3 Months Ended
	Mar. 31, 2021
Regulated Operations [Abstract]
Schedule of Regulatory Assets and Regulatory Liabilities	Details of the regulatory assets and liabilities are presented in the following table: Regulatory Assets and Liabilities (millions) March 31, 2021 December 31, 2020 Regulatory assets: Regulatory tax asset (1) $ 96 $ 90 Cost-recovery clauses (2) 35 38 Environmental remediation (3) 23 22 Postretirement benefits (4) 303 309 Asset retirement obligation (5) 12 13 Other 11 13 Total regulatory assets 480 485 Less: Current portion 64 79 Long-term regulatory assets $ 416 $ 406 Regulatory liabilities: Regulatory tax liability (6) $ 691 $ 691 Cost-recovery clauses (2) 17 23 Accumulated reserve - cost of removal (7) 494 498 Storm reserve (8) 48 48 Other 2 1 Total regulatory liabilities 1,252 1,261 Less: Current portion 62 67 Long-term regulatory liabilities $ 1,190 $ 1,194 The regulatory tax asset is primarily associated with the depreciation and recovery of AFUDC-equity. This asset does not earn a return but rather is included in the capital structure, which is used in the calculation of the weighted cost of capital used to determine revenue requirements. It will be recovered over the expected life of the related assets. The regulatory tax asset balance reflects the impact of the federal tax rate reduction. (2) These assets and liabilities are related to FPSC clauses and riders. They are recovered or refunded through cost-recovery mechanisms approved by the FPSC on a dollar-for-dollar basis in a subsequent period. (3) This asset is related to costs associated with environmental remediation primarily at MGP sites. The balance is included in rate base, partially offsetting the related liability, and earns a rate of return as permitted by the FPSC. The timing of recovery is based on a settlement agreement approved by the FPSC. (4) This asset is related to the deferred costs of postretirement benefits and it is amortized over the remaining service life of plan participants. Deferred costs of postretirement benefits that are included in expense are recognized as cost of service for rate-making purposes as permitted by the FPSC. (5) This asset is related to costs associated with an asset retirement obligation, which is a legal obligation for the future retirement of certain tangible, long-lived assets. This regulatory asset does not earn a return because it is offset with related assets and liabilities within rate base. It is recovered and removed as the obligation is settled and removed as the activities for the retirement of the related assets have been completed. (6) The regulatory tax liability is primarily related to the revaluation of TEC’s deferred income tax balances recorded on December 31, 2017 at the lower income tax rate due to U.S. tax reform. The liability related to the revaluation of the deferred income tax balances is amortized and returned to customers through rate reductions or other revenue offsets based on IRS regulations and the settlement agreement for tax reform benefits approved by the FPSC. (7) This item represents the non-ARO cost of removal in the accumulated reserve for depreciation. AROs are costs for legally required removal of property, plant and equipment. Non-ARO cost of removal represents estimated funds received from customers through depreciation rates to cover future non-legally required cost of removal of property, plant and equipment, net of salvage value upon retirement, which reduces rate base for ratemaking purposes. This liability is reduced as costs of removal are incurred. (8) As a result of Tampa Electric’s 2013 rate case settlement, in the event of a named storm that results in damage to its system, Tampa Electric can petition the FPSC to seek recovery of those costs over a 12-month period or longer as determined by the FPSC, as well as replenish its reserve to $56 million, the level of the reserve as of October 31, 2013. In 2019, Tampa Electric incurred storm restoration preparation costs for Hurricane Dorian of approximately $8 million, which was charged to the storm reserve regulatory liability.

Employee Postretirement Benef_2

Employee Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2021
TECO Energy [Member]
Schedule of Net Periodic Benefit Cost	The following table presents detail related to TECO Energy’s periodic benefit cost for pension and other postretirement benefits. Amounts disclosed for TECO Energy’s pension benefits include the amounts related to its qualified pension plan and non-qualified, non-contributory SERP and Restoration Plan. TECO Energy Benefit Cost (millions) Pension Benefits Other Postretirement Benefits Three months ended March 31, 2021 2020 2021 2020 Components of net periodic benefit cost Service cost $ 5 $ 5 $ 0 $ 0 Interest cost 5 7 1 1 Expected return on assets (13 ) (13 ) 0 0 Amortization of: Actuarial loss (gain) 6 5 1 0 Net periodic benefit cost $ 3 $ 4 $ 2 $ 1

Short-Term Debt (Tables)

Short-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Short-Term Debt Credit Facilities and Related Borrowings	Details of TEC’s credit facilities and related borrowings are presented in the following table: March 31, 2021 December 31, 2020 Letters Letters Credit Borrowings of Credit Credit Borrowings of Credit (millions) Facilities Outstanding (1) Outstanding Facilities Outstanding (1) Outstanding 5-year facility (2) $ 800 $ 10 $ 1 $ 800 $ 345 $ 1 3-year accounts receivable facility (3) 0 0 0 150 130 0 1-year term facility (4) 0 0 0 300 300 0 Total $ 800 $ 10 $ 1 $ 1,250 $ 775 $ 1 (1) Borrowings outstanding are reported as notes payable. (2) This 5-year facility matures March 22, 2023. (3) This 3-year facility matured on March 22, 2021. (4) This 1-year term facility was terminated on March 23, 2021.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Schedule of Long-term Commitments	The following is a schedule of future payments under PPAs, minimum lease payments with non-cancelable lease terms in excess of one year, and other net purchase obligations/commitments at March 31, 2021: Long-term Demand Purchased Capital Fuel and Service Operating Side (millions) Power Transportation Projects Gas Supply Agreements Leases Management Total 2021 $ 35 $ 175 $ 300 $ 197 $ 10 $ 2 $ 3 $ 722 2022 0 233 75 42 12 3 3 368 2023 0 212 57 1 15 3 0 288 2024 0 207 0 0 15 3 0 225 2025 0 188 0 0 16 2 0 206 Thereafter 0 1,998 0 0 54 48 0 2,100 Total future minimum payments $ 35 $ 3,013 $ 432 $ 240 $ 122 $ 61 $ 6 $ 3,909

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Schedule of Segment Information	(millions) Tampa Tampa Electric Three months ended March 31, Electric PGS Eliminations Company 2021 Revenues - external $ 446 $ 153 $ 0 $ 599 Intracompany sales 1 2 (3 ) 0 Total revenues 447 155 (3 ) 599 Total interest charges 28 5 0 33 Net income $ 65 $ 27 $ 0 $ 92 2020 Revenues - external $ 420 $ 127 $ 0 $ 547 Intracompany sales 1 2 (3 ) 0 Total revenues 421 129 (3 ) 547 Total interest charges 30 4 0 34 Net income $ 59 $ 18 $ 0 $ 77 Total assets at March 31, 2021 $ 9,909 $ 1,968 $ (669 ) (1) $ 11,208 Total assets at December 31, 2020 $ 9,800 $ 1,901 $ (653 ) (1) $ 11,048 (1) Amounts primarily relate to consolidated deferred tax reclassifications. Deferred tax assets are reclassified and netted with deferred tax liabilities upon consolidation.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue Recognition [Abstract]
Summary of Disaggregates TEC Revenue by Major Source	The following disaggregates TEC’s revenue by major source: (millions) Tampa Tampa Electric Three months ended March 31, 2021 Electric PGS Eliminations Company Electric revenue Residential $ 232 $ 0 $ 0 $ 232 Commercial 126 0 0 126 Industrial 37 0 0 37 Regulatory deferrals and unbilled revenue (2 ) 0 0 (2 ) Other (1) 54 0 (1 ) 53 Total electric revenue 447 0 (1 ) 446 Gas revenue Residential 0 67 0 67 Commercial 0 53 0 53 Industrial (2) 0 6 0 6 Other (3) 0 29 (2 ) 27 Total gas revenue 0 155 (2 ) 153 Total revenue $ 447 $ 155 $ (3 ) $ 599 Three months ended March 31, 2020 Electric revenue Residential $ 205 $ 0 $ 0 $ 205 Commercial 125 0 0 125 Industrial 37 0 0 37 Regulatory deferrals and unbilled revenue (2 ) 0 0 (2 ) Other (1) 56 0 (1 ) 55 Total electric revenue 421 0 (1 ) 420 Gas revenue Residential 0 48 0 48 Commercial 0 41 0 41 Industrial (2) 0 6 0 6 Other (3) 0 34 (2 ) 32 Total gas revenue 0 129 (2 ) 127 Total revenue $ 421 $ 129 $ (3 ) $ 547 (1) Other electric revenue includes sales to public authorities, off-system sales to other utilities and various other items. (2) Industrial gas revenue includes sales to power generation customers. (3) Other gas revenue includes off-system sales to other utilities and various other items.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Receivables from contracts with customers	$ 220		$ 214
Unbilled revenues	74		$ 73
Franchise fees and gross receipts taxes	$ 29	$ 27

Regulatory - Additional Informa

Regulatory - Additional Information (Detail) $ in Millions

Nov. 19, 2020USD ($)

Aug. 18, 2020USD ($)

Aug. 03, 2020USD ($)

Apr. 27, 2020USD ($)

Jun. 28, 2019USD ($)MW

Jun. 29, 2018USD ($)MW

Dec. 12, 2017USD ($)MW

Sep. 27, 2017USD ($)MW

Mar. 31, 2021USD ($)

Mar. 31, 2020USD ($)

Jan. 31, 2022USD ($)

Apr. 09, 2021USD ($)

Dec. 31, 2020USD ($)

Jun. 09, 2020USD ($)

Public Utilities General Disclosures [Line Items]

Utility plant, at original costs

$ 14,053

$ 13,818

Accumulated depreciation

3,792

3,712

Increase in amortization of regulatory asset associated with environmental remediation costs

0

$ 12

Intangible Software Assets [Member]

Public Utilities General Disclosures [Line Items]

Accumulated amortization reserve surplus

$ 16

Electric Utility Plant [Member]

Public Utilities General Disclosures [Line Items]

Utility plant, at original costs

11,646

11,486

Peoples Gas System [Member]

Public Utilities General Disclosures [Line Items]

Accumulated depreciation

$ 34

Increase in annual base rate

58

Increase in revenue

$ 34

Allowed equity in the capital structure

54.70%

Impact of tax reform through reduction in base revenue days

120 days

Peoples Gas System [Member] | 2017 Settlement Agreement [Member]

Public Utilities General Disclosures [Line Items]

Increase in amortization of regulatory asset associated with environmental remediation costs

32

Reduction in annual depreciation expense

$ 16

Regulatory asset amortization beginning period

2016

Regulatory asset amortization ending period

2020

Peoples Gas System [Member] | Cast Iron and Bare Steel Replacement Rider [Member]

Public Utilities General Disclosures [Line Items]

Increase in revenue

$ 24

Subsequent Event

Public Utilities General Disclosures [Line Items]

Base rate adjustment amount

$ 130

Scenario Forecast [Member]

Public Utilities General Disclosures [Line Items]

Revenue requirements

$ 295

Minimum [Member] | Peoples Gas System [Member]

Public Utilities General Disclosures [Line Items]

Percentage of ROE

8.90%

Base rate agreement frozen period

Jan. 1, 2021

Minimum [Member] | Peoples Gas System [Member] | 2017 Settlement Agreement [Member]

Public Utilities General Disclosures [Line Items]

Percentage of ROE

9.25%

Maximum [Member] | Peoples Gas System [Member]

Public Utilities General Disclosures [Line Items]

Percentage of ROE

11.00%

Base rate agreement frozen period

Dec. 31, 2023

Maximum [Member] | Peoples Gas System [Member] | 2017 Settlement Agreement [Member]

Public Utilities General Disclosures [Line Items]

Percentage of ROE

11.75%

Mid Point [Member] | Peoples Gas System [Member]

Public Utilities General Disclosures [Line Items]

Percentage of ROE

9.90%

Solar Project Cost Recovery [Member]

Public Utilities General Disclosures [Line Items]

Settlement agreement, extended terms

four years through December 31, 2021

Settlement agreement, approval date

Nov. 6, 2017

Solar energy capacity | MW

600

Solar generation capacity investments

$ 850

Solar Project Cost Recovery [Member] | Solar Base Rate Adjustments [Member]

Public Utilities General Disclosures [Line Items]

True-up amount returned to customers

$ 5

Solar Project Cost Recovery [Member] | Effective September 1, 2018 [Member]

Public Utilities General Disclosures [Line Items]

Solar energy capacity | MW

145

Estimated annual revenue requirements

$ 24

Solar Project Cost Recovery [Member] | Effective January 1, 2019 [Member]

Public Utilities General Disclosures [Line Items]

Solar energy capacity | MW

260

Estimated annual revenue requirements

$ 46

Solar Project Cost Recovery [Member] | Effective January 1, 2020 [Member]

Public Utilities General Disclosures [Line Items]

Solar energy capacity | MW

149

Estimated annual revenue requirements

$ 26

Solar Project Cost Recovery [Member] | Effective January 1, 2021 [Member]

Public Utilities General Disclosures [Line Items]

Solar energy capacity | MW

46

Estimated annual revenue requirements

$ 8

Solar Project Cost Recovery [Member] | Minimum [Member]

Public Utilities General Disclosures [Line Items]

Solar project investment term

2017

Solar Project Cost Recovery [Member] | Maximum [Member]

Public Utilities General Disclosures [Line Items]

Solar project investment term

2021

Big Bend Modernization Project [Member]

Public Utilities General Disclosures [Line Items]

Energy generation capacity investments

$ 850

Investments in energy projects till date

574

Accumulated depreciation

89

88

Big Bend Modernization Project [Member] | Electric Utility Plant [Member]

Public Utilities General Disclosures [Line Items]

Utility plant, at original costs

$ 200

$ 200

Big Bend Modernization Project [Member] | Minimum [Member]

Public Utilities General Disclosures [Line Items]

Energy project investment term

2018

Big Bend Modernization Project [Member] | Maximum [Member]

Public Utilities General Disclosures [Line Items]

Energy project investment term

2023

Storm Protection Plan [Member]

Public Utilities General Disclosures [Line Items]

Reduction in annual base rates

$ 15

Cost recovery from settlement agreement

$ 39

Regulatory - Schedule of Regula

Regulatory - Schedule of Regulatory Assets and Regulatory Liabilities (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Regulatory assets:
Regulatory assets	$ 480	$ 485
Less: Current portion	64	79
Long-term regulatory assets	416	406
Regulatory liabilities:
Regulatory liabilities	1,252	1,261
Less: Current portion	62	67
Long-term regulatory liabilities	1,190	1,194
Regulatory Tax Asset [Member]
Regulatory assets:
Regulatory assets	96	90
Cost-Recovery Clauses [Member]
Regulatory assets:
Regulatory assets	35	38
Environmental Remediation [Member]
Regulatory assets:
Regulatory assets	23	22
Postretirement Benefits [Member]
Regulatory assets:
Regulatory assets	303	309
Asset Retirement Obligation [Member]
Regulatory assets:
Regulatory assets	12	13
Other [Member]
Regulatory assets:
Regulatory assets	11	13
Regulatory Tax Liability [Member] | Non-Current Liabilities [Member]
Regulatory liabilities:
Regulatory liabilities	691	691
Cost-Recovery Clauses [Member]
Regulatory liabilities:
Regulatory liabilities	17	23
Storm Reserve [Member]
Regulatory liabilities:
Regulatory liabilities	48	48
Accumulated Reserve - Cost of Removal [Member]
Regulatory liabilities:
Regulatory liabilities	494	498
Other [Member]
Regulatory liabilities:
Regulatory liabilities	$ 2	$ 1

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Income Taxes [Line Items]
Unrecognized tax benefits	$ 5		$ 9
Unrecognized tax benefit that would reduce effective tax rate	5		$ 9
Federal [Member] | R&D Tax Credits [Member]
Income Taxes [Line Items]
Unrecognized tax benefits decreased	$ 5
Tampa Electric [Member]
Income Taxes [Line Items]
Effective tax rate	17.90%	17.20%

Employee Postretirement Benef_3

Employee Postretirement Benefits - Schedule of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Benefits [Member]
Amortization of:
Net periodic benefit cost	$ 3	$ 3
Other Postretirement Benefits [Member]
Amortization of:
Net periodic benefit cost	2	2
TECO Energy [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5
Interest cost	5	7
Expected return on assets	(13)	(13)
Amortization of:
Actuarial loss (gain)	6	5
Net periodic benefit cost	3	4
TECO Energy [Member] | Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	1	1
Expected return on assets	0	0
Amortization of:
Actuarial loss (gain)	1	0
Net periodic benefit cost	$ 2	$ 1

Employee Postretirement Benef_4

Employee Postretirement Benefits - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Reclassification of regulatory assets to net income as part of periodic benefit cost	$ 6	$ 4
TECO Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Long-term EROA	6.70%
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ 3	3
Employer contributions	4	4
Employer contributions in remainder of year	13
Pension Benefits [Member] | TECO Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ 3	4
Discount rate	2.38%
Employer contributions	$ 5	5
Employer contributions in remainder of year	16
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	2	2
Other Postretirement Benefits [Member] | TECO Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ 2	$ 1
Discount rate	2.47%

Short-Term Debt - Credit Facili

Short-Term Debt - Credit Facilities and Related Borrowings (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 18, 2020	Oct. 30, 2020	Jul. 14, 2020
Line Of Credit Facility [Line Items]
Credit Facilities	$ 800,000,000	$ 1,250,000,000	$ 80,000,000
Borrowings Outstanding	10,000,000	775,000,000
Letters of Credit Outstanding	1,000,000	1,000,000
5-year Facility [Member]
Line Of Credit Facility [Line Items]
Credit Facilities	800,000,000	800,000,000
Borrowings Outstanding	10,000,000	345,000,000
Letters of Credit Outstanding	1,000,000	1,000,000
1-year Term Facility [Member]
Line Of Credit Facility [Line Items]
Credit Facilities	0	300,000,000
Borrowings Outstanding	0	300,000,000
Letters of Credit Outstanding	0	0
3-year Accounts Receivable Facility [Member]
Line Of Credit Facility [Line Items]
Credit Facilities	0	150,000,000		$ 150,000,000	$ 150,000,000
Borrowings Outstanding	0	130,000,000
Letters of Credit Outstanding	$ 0	$ 0

Short-Term Debt - Credit Faci_2

Short-Term Debt - Credit Facilities and Related Borrowings (Parenthetical) (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
5-year Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility maturity date	Mar. 22, 2023	Mar. 22, 2023
3-year Accounts Receivable Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility maturity date	Mar. 22, 2021	Mar. 22, 2021
1-year Term Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility maturity date	Sep. 30, 2021	Sep. 30, 2021

Short-Term Debt - Additional In

Short-Term Debt - Additional Information (Detail) - USD ($)	Jan. 29, 2021	Dec. 18, 2020	Oct. 30, 2020	Jul. 14, 2020	Feb. 06, 2020	Mar. 31, 2021	Dec. 31, 2020
Line Of Credit Facility [Line Items]
Commitment fees, percentage						0.125%
Weighted-average interest rate						0.99%	0.89%
Line of credit facility maximum borrowing capacity		$ 80,000,000				$ 800,000,000	$ 1,250,000,000
Lenders commitment amount		800,000,000
Increase of credit facility		$ 100,000,000
Minimum [Member] | Amended And Restated Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Debt instrument maturity date		Mar. 22, 2022
Maximum [Member] | Amended And Restated Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Debt instrument maturity date		Mar. 22, 2023
3-year Accounts Receivable Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility amendment date			Oct. 30, 2020	Jul. 14, 2020
Line of credit facility maximum borrowing capacity			$ 150,000,000	$ 150,000,000		$ 0	$ 150,000,000
Credit facility maturity date						Mar. 22, 2021	Mar. 22, 2021
364-day Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity					$ 300,000,000
Credit facility maturity date					Feb. 4, 2021
Credit facility maturity period					364 days
Credit Facility extended maturity date	Apr. 29, 2021

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Detail) - USD ($) $ in Millions	Mar. 18, 2021	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt		$ 3,664	$ 2,872
Estimated fair value		$ 4,136	$ 3,597
2.40% Notes [Member]
Debt Instrument [Line Items]
Debt instrument, maturity year	2031
Aggregate principal amount issued	$ 400
Stated interest rate	2.40%
Debt instrument maturity date	Mar. 15, 2031
Redeemable principal amount percentage	100.00%
Basis spread on federal funds rate	0.15%
Redeemable principal amount percentage	100.00%
Debt instrument, start date of redemption	Dec. 15, 2030
Debt instrument, offering date	Mar. 18, 2021
3.45% Notes [Member]
Debt Instrument [Line Items]
Debt instrument, maturity year	2051
Aggregate principal amount issued	$ 400
Stated interest rate	3.45%
Debt instrument maturity date	Mar. 15, 2051
Redeemable principal amount percentage	100.00%
Basis spread on federal funds rate	0.20%
Redeemable principal amount percentage	100.00%
Debt instrument, start date of redemption	Sep. 15, 2050
Debt instrument, offering date	Mar. 18, 2021

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
PGS [Member]
Long Term Commitments [Line Items]
Ultimate financial liability to superfund sites and former MGP sites	$ 17	$ 17

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Long-term Commitments (Detail) $ in Millions	Mar. 31, 2021USD ($)
Other Commitments [Line Items]
2021	$ 722
2022	368
2023	288
2024	225
2025	206
Thereafter	2,100
Total future minimum payments	3,909
Purchased Power [Member]
Other Commitments [Line Items]
2021	35
2022	0
2023	0
2024	0
2025	0
Thereafter	0
Total future minimum payments	35
Transportation [Member]
Other Commitments [Line Items]
2021	175
2022	233
2023	212
2024	207
2025	188
Thereafter	1,998
Total future minimum payments	3,013
Capital Projects [Member]
Other Commitments [Line Items]
2021	300
2022	75
2023	57
2024	0
2025	0
Thereafter	0
Total future minimum payments	432
Fuel and Gas Supply [Member]
Other Commitments [Line Items]
2021	197
2022	42
2023	1
2024	0
2025	0
Thereafter	0
Total future minimum payments	240
Long-term Service Agreements [Member]
Other Commitments [Line Items]
2021	10
2022	12
2023	15
2024	15
2025	16
Thereafter	54
Total future minimum payments	122
Operating Leases [Member]
Other Commitments [Line Items]
2021	2
2022	3
2023	3
2024	3
2025	2
Thereafter	48
Total future minimum payments	61
Demand Side Management [Member]
Other Commitments [Line Items]
2021	3
2022	3
2023	0
2024	0
2025	0
Thereafter	0
Total future minimum payments	$ 6

Segment Information - Schedule

Segment Information - Schedule of Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total revenues	$ 599	$ 547
Total interest charges	33	34
Net income	92	77
Total assets	11,208		$ 11,048
Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	599	547
Intracompany Sales [Member]
Segment Reporting Information [Line Items]
Intracompany sales	0	0
Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	(3)	(3)
Total interest charges	0	0
Net income	0	0
Total assets	(669)		(653)
Eliminations [Member] | Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0
Eliminations [Member] | Intracompany Sales [Member]
Segment Reporting Information [Line Items]
Intracompany sales	(3)	(3)
Tampa Electric [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	447	421
Total interest charges	28	30
Net income	65	59
Total assets	9,909		9,800
Tampa Electric [Member] | Operating Segments [Member] | Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	446	420
Tampa Electric [Member] | Operating Segments [Member] | Intracompany Sales [Member]
Segment Reporting Information [Line Items]
Intracompany sales	1	1
PGS [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	155	129
Total interest charges	5	4
Net income	27	18
Total assets	1,968		$ 1,901
PGS [Member] | Operating Segments [Member] | Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	153	127
PGS [Member] | Operating Segments [Member] | Intracompany Sales [Member]
Segment Reporting Information [Line Items]
Intracompany sales	$ 2	$ 2

Revenue - Summary of Disaggrega

Revenue - Summary of Disaggregates TEC Revenue by Major Source (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation Of Revenue [Line Items]
Total electric revenue	$ 446	$ 420
Total gas revenue	153	127
Total revenue	599	547
Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	232	205
Total gas revenue	67	48
Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	126	125
Total gas revenue	53	41
Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	37	37
Total gas revenue	6	6
Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(2)	(2)
Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	53	55
Total gas revenue	27	32
Operating Segments [Member] | Tampa Electric [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	447	421
Total gas revenue	0	0
Total revenue	447	421
Operating Segments [Member] | Tampa Electric [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	232	205
Total gas revenue	0	0
Operating Segments [Member] | Tampa Electric [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	126	125
Total gas revenue	0	0
Operating Segments [Member] | Tampa Electric [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	37	37
Total gas revenue	0	0
Operating Segments [Member] | Tampa Electric [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(2)	(2)
Operating Segments [Member] | Tampa Electric [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	54	56
Total gas revenue	0	0
Operating Segments [Member] | PGS [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	155	129
Total revenue	155	129
Operating Segments [Member] | PGS [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	67	48
Operating Segments [Member] | PGS [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	53	41
Operating Segments [Member] | PGS [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	6	6
Operating Segments [Member] | PGS [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Operating Segments [Member] | PGS [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	29	34
Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(1)	(1)
Total gas revenue	(2)	(2)
Total revenue	(3)	(3)
Eliminations [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	0	0
Eliminations [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	0	0
Eliminations [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Total gas revenue	0	0
Eliminations [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0
Eliminations [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(1)	(1)
Total gas revenue	$ (2)	$ (2)

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Regulated Operating Revenue [Abstract]
Remaining performance obligations, transaction price	$ 131	$ 135
Remaining performance obligations, expected year of revenue recognition	2033