Long-Term Debt (Based on Stated Maturity Dates Rather than Early Redemption Dates that Could be Elected by Instrument Holders) (Detail) $ in Millions	Dec. 31, 2024 USD ($)
Debt Instrument [Line Items]
2025	$ 1,663
2026	2,291
2027	1,963
2028	1,477
2029	698
Thereafter	31,228
Total	$ 39,320
Weighted- average coupon, 2025	3.70%
Weighted- average coupon, 2026	2.80%
Weighted- average coupon, 2027	3.86%
Weighted- average coupon, 2028	4.11%
Weighted- average coupon, 2029	3.44%
Weighted- average coupon, Thereafter	4.87%
First mortgage bonds
Debt Instrument [Line Items]
2025	$ 0
2026	0
2027	0
2028	53
2029	0
Thereafter	4,081
Total	4,134
Unsecured senior notes
Debt Instrument [Line Items]
2025	1,500
2026	2,120
2027	1,783
2028	1,195
2029	500
Thereafter	22,864
Total	29,962
Senior secured deferred fuel cost bonds
Debt Instrument [Line Items]
2025	163
2026	171
2027	180
2028	190
2029	198
Thereafter	315
Total	1,217
Tax-exempt financings
Debt Instrument [Line Items]
2025	0
2026	0
2027	0
2028	39
2029	0
Thereafter	708
Total	747
Junior Subordinated Notes
Debt Instrument [Line Items]
2025	0
2026	0
2027	0
2028	0
2029	0
Thereafter	3,260
Total	3,260
Virginia Electric and Power Company
Debt Instrument [Line Items]
2025	513
2026	1,321
2027	1,530
2028	890
2029	698
Thereafter	15,675
Total	$ 20,627
Weighted- average coupon, 2025	3.73%
Weighted- average coupon, 2026	3.34%
Weighted- average coupon, 2027	3.77%
Weighted- average coupon, 2028	4.03%
Weighted- average coupon, 2029	3.44%
Weighted- average coupon, Thereafter	4.58%
Virginia Electric and Power Company | Unsecured senior notes
Debt Instrument [Line Items]
2025	$ 350
2026	1,150
2027	1,350
2028	700
2029	500
Thereafter	14,735
Total	18,785
Virginia Electric and Power Company | Senior secured deferred fuel cost bonds
Debt Instrument [Line Items]
2025	163
2026	171
2027	180
2028	190
2029	198
Thereafter	315
Total	1,217
Virginia Electric and Power Company | Tax-exempt financings
Debt Instrument [Line Items]
2025	0
2026	0
2027	0
2028	0
2029	0
Thereafter	625
Total	$ 625