Virginia Electric and Power Company Consolidated Statements of Common Shareholder's Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	AOCI	Virginia Electric and Power Company	Virginia Electric and Power Company Cumulative-effect of Changes in Accounting Principles	Virginia Electric and Power Company Common Stock	Virginia Electric and Power Company Other Paid-In Capital	Virginia Electric and Power Company Retained Earnings	Virginia Electric and Power Company Retained Earnings Cumulative-effect of Changes in Accounting Principles	Virginia Electric and Power Company AOCI	Virginia Electric and Power Company AOCI Cumulative-effect of Changes in Accounting Principles
Beginning balance at Dec. 31, 2017				$ 12,224	$ 3	$ 5,738	$ 1,113	$ 5,311	$ 79	$ 62	$ (76)
Beginning balance (in shares) at Dec. 31, 2017		645,000				275
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member			us-gaap:AccountingStandardsUpdate201613Member
Net income	$ 2,447			$ 1,282				1,282
Dividends				(464)				(464)
Other comprehensive income (loss), net of tax	(17)		$ (18)	2						2
Ending balance at Dec. 31, 2018			(1,700)	13,047		$ 5,738	1,113	6,208		(12)
Ending Balance (in shares) at Dec. 31, 2018		681,000				275
Net income	1,358			1,149				1,149
Dividends				(190)				(190)
Other comprehensive income (loss), net of tax	(93)		(93)	(17)						(17)
Ending balance at Dec. 31, 2019	$ 31,994		(1,793)	13,989		$ 5,738	1,113	7,167		(29)
Ending Balance (in shares) at Dec. 31, 2019		838,000				275
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Net income	$ (401)			1,021				1,021
Dividends				(430)				(430)
Other comprehensive income (loss), net of tax	76		76	(23)						(23)
Ending balance at Dec. 31, 2020	$ 26,117		$ (1,717)	$ 14,557		$ 5,738	$ 1,113	$ 7,758		$ (52)
Ending Balance (in shares) at Dec. 31, 2020		806,000				275