Related Party Transactions - Schedule of Related Parties (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Natural gas sales to/(from) affiliates	$ (232)	$ (236)	$ (139)
Services received from affiliates	4	7	6
Dividends to TECO Energy	517	450	408
Equity contributions from TECO Energy	605	580	505
Affiliate [Member]
Related Party Transaction [Line Items]
Accounts receivable excluding asset management agreements	5	4
Taxes receivable	10	0
Accounts payable	31	35
Note payable to TECO Energy	195	0
Taxes payable	0	9
Emera Energy Services Inc [Member]
Related Party Transaction [Line Items]
Accounts receivable related to asset management agreements to Emera Energy Services Inc.	7	4
TECO Energy [Member]
Related Party Transaction [Line Items]
Dividends to TECO Energy	517	450	408
Equity contributions from TECO Energy	$ 605	$ 580	$ 505

Accounts receivable excluding asset management agreements.

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Accounts receivable related to asset management agreements.

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Natural gas sales to (from) affiliates.

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Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

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Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes.

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes.

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