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Debt Issuance Costs, Net of Taxes

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Fair Value of Financial Instruments.

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Gain (Loss) on Fair Value Hedges Recognized in Earnings, Net

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Investment, Ownership Percentage Pledged as Collateral

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Investments not required to be disclosed.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt premium.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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Amount of realized and unrealized gain (loss) on investment.

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Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Dividends received on equity and other investments during the current period.

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Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions			3 Months Ended		6 Months Ended
	Jun. 15, 2022	Jan. 27, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	May 25, 2022	May 23, 2022	Apr. 22, 2022	Apr. 15, 2022	Dec. 31, 2021
Fair Value of Financial Instruments [Line Items]
Investments not required to be disclosed			$ 357		$ 357						$ 371
Debt issuance costs	$ 10
Debt issuance costs, after tax	8
Losses on deferred cash flows	7
Losses on deferred cash flows, net	5
Corporate-Owned Life Insurance
Fair Value of Financial Instruments [Line Items]
Gain (loss) on investments			$ (16)	$ 6	$ (22)	$ 8
FEV \| Global Holding
Fair Value of Financial Instruments [Line Items]
Investment ownership percentage			33.30%		33.30%
Equity method investments			$ 65		$ 65						59
Proceeds from dividends received			70
FEV \| Global Holding \| Corporate and Other \| Other Nonoperating Income (Expense)
Fair Value of Financial Instruments [Line Items]
Income from equity method investments			64	$ 4	76	$ 4
Senior Notes
Fair Value of Financial Instruments [Line Items]
Make-whole premium	101
Early repayment of debt	1,100
Make-whole premium, net	80
4.25% Series B Senior Notes Due 2023 \| Senior Notes
Fair Value of Financial Instruments [Line Items]
Face amount of debt											850
Make-whole premium											38
Make-whole premium, net											$ 30
2.77% Series A Senior Notes Due 2034 \| Senior Notes \| The Cleveland Electric Illuminating Company
Fair Value of Financial Instruments [Line Items]
Face amount of debt		$ 150
Stated interest rate		2.77%
2.65%, 150 Million Notes Maturing 2028 \| Senior Notes \| TE
Fair Value of Financial Instruments [Line Items]
Stated interest rate		2.65%
Early repayment of debt		$ 25
3.34% FMB's Due April 2022 \| First Mortgage Bond \| WP
Fair Value of Financial Instruments [Line Items]
Face amount of debt										$ 100
Stated interest rate										3.34%
3.79%, 150 Million FMB's Due December 2032 \| First Mortgage Bond \| Penn
Fair Value of Financial Instruments [Line Items]
Face amount of debt									$ 150
Stated interest rate									3.79%
$500 Million 2.85% Notes \| Senior Notes
Fair Value of Financial Instruments [Line Items]
Face amount of debt								$ 500
Stated interest rate								2.85%
6.5% $100 Million FMB's Due June 2022 \| First Mortgage Bond \| Penn
Fair Value of Financial Instruments [Line Items]
Face amount of debt			$ 100		$ 100
Stated interest rate			6.09%		6.09%
Series C 7.375% Senior Notes Due 2031 \| Senior Notes
Fair Value of Financial Instruments [Line Items]
Early repayment of debt	715
Debt outstanding							$ 1,500
Series C 4.85% Senior Notes Due 2047 \| Senior Notes
Fair Value of Financial Instruments [Line Items]
Early repayment of debt	$ 284
Debt outstanding							$ 1,000