Significant Accounting Policies (Schedule of Supplemental Cash Flow Information) (Detail) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021
Significant noncash investing and financing activities:(1)
Accrued capital expenditures	[1]	$ 512	$ 327
Accrued contributions to equity method affiliates	[1]		20
Leases	[2]	57	29
Virginia Electric and Power Company
Significant noncash investing and financing activities:(1)
Accrued capital expenditures		240	207
Leases	[3]	$ 47	$ 17

[1] See Note 16 for noncash financing activities related to the remarketing of Series A Preferred Stock and the issuance of common stock associated with the settlement of litigation.

[2] See Note 16 for noncash financing activities related to the remarketing of Series A Preferred Stock and the issuance of common stock associated with the settlement of litigation.

[3] Includes $14 million and $17 million of financing leases at June 30, 2022 and 2021, respectively, and $33 million of operating leases at June 30, 2022