Income Taxes	3 Months Ended
Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	6. INCOME TAXES DESC has recorded an estimate of excess deferred income tax amortization in 2020. The reversal of these excess deferred income taxes will impact the effective tax rate and rates charged to customers. See Note 3 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2019 for more information. DESC’s effective tax rate for the three months ended March 31, 2020 is 19.9% compared to 9.7% for the three months ended March 31, 2019. Variances in the effective tax rate are primarily driven by charges resulting from the SCANA Combination. In connection with the SCANA Merger Approval Order, Dominion Energy committed to forgo, or limit, the recovery of certain income tax-related regulatory assets associated with the NND Project. DESC's 2019 effective tax rate reflects income tax expense of $198 million in satisfaction of this commitment. Also in the first quarter 2019, DESC’s unrecognized tax benefits increased by $51 million and income tax expense increased by $40 million related to a state income tax position taken in prior years. In March 2020, the CARES Act was enacted which includes several significant business tax provisions that modify or temporarily suspend certain provisions of the 2017 Tax Reform Act. The CARES Act provisions are intended to improve cash flow and liquidity by, among other things, providing a temporary five-year carryback for certain net operating losses, accelerating the refund of previously generated corporate alternative minimum tax credits, and temporarily loosening the business interest limitation to 50% of adjusted taxable income for certain businesses. While DESC intends to utilize the income tax provisions of the CARES Act to accelerate the recognition of certain tax attributes, where applicable, they are not expected to provide a material benefit. As of March 31, 2020, there have been no other material changes in DESC’s unrecognized tax benefits. See Note 7 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2019 for a discussion of these unrecognized tax benefits.

Income Taxes

3 Months Ended

Mar. 31, 2020

6. INCOME TAXES

DESC has recorded an estimate of excess deferred income tax amortization in 2020. The reversal of these excess deferred income taxes will impact the effective tax rate and rates charged to customers. See Note 3 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2019 for more information.

DESC’s effective tax rate for the three months ended March 31, 2020 is 19.9% compared to 9.7% for the three months ended March 31, 2019. Variances in the effective tax rate are primarily driven by charges resulting from the SCANA Combination. In connection with the SCANA Merger Approval Order, Dominion Energy committed to forgo, or limit, the recovery of certain income tax-related regulatory assets associated with the NND Project. DESC's 2019 effective tax rate reflects income tax expense of $198 million in satisfaction of this commitment. Also in the first quarter 2019, DESC’s unrecognized tax benefits increased by $51 million and income tax expense increased by $40 million related to a state income tax position taken in prior years.

In March 2020, the CARES Act was enacted which includes several significant business tax provisions that modify or temporarily suspend certain provisions of the 2017 Tax Reform Act. The CARES Act provisions are intended to improve cash flow and liquidity by, among other things, providing a temporary five-year carryback for certain net operating losses, accelerating the refund of previously generated corporate alternative minimum tax credits, and temporarily loosening the business interest limitation to 50% of adjusted taxable income for certain businesses. While DESC intends to utilize the income tax provisions of the CARES Act to accelerate the recognition of certain tax attributes, where applicable, they are not expected to provide a material benefit.

As of March 31, 2020, there have been no other material changes in DESC’s unrecognized tax benefits. See Note 7 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2019 for a discussion of these unrecognized tax benefits.