TAXES - Accumulated Deferred Income Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated deferred income taxes
Property basis differences	$ 5,396	$ 5,037
Pension and OPEB	(769)	(698)
TMI-2 nuclear decommissioning	0	89
AROs	(28)	(226)
Regulatory asset/liability	440	445
Deferred compensation	(165)	(154)
Estimated worthless stock deduction	0	(1,007)
Loss carryforwards and AMT credits	(1,995)	(836)
Valuation reserve	496	441	$ 394	$ 312
All other	(280)	(242)
Net deferred income tax liability	$ 3,095	$ 2,849

Deferred Tax Assets Liabilities, Net, Asset Retirement Obligation Liability

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Deferred Tax Assets Liabilities Net Non current Loss carry forward valuation reserve.

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Deferred Tax Assets Liabilities Net Non current Loss carry forwards and Tax Credits

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Deferred Tax Assets Liabilities Net Non current Nuclear decommissioning activities.

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Deferred Tax Assets Liabilities, Net, Worthless Stock Deduction

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from employee compensation.

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.

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Amount of deferred tax liability attributable to taxable temporary differences from the entity's basis in a discontinued operation.

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Amount of deferred tax liability attributable to taxable temporary differences from regulatory assets and liabilities.

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