Organization and Basis of Presentation (Schedule of New Accounting Pronouncements) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	$ 47,951	$ 46,611	$ 48,083	$ 45,332	$ 45,045	$ 43,834
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Progress Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	$ 15,593	16,221	15,877	14,839	14,508	14,257
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	4,108	2,707	4,221	3,502	3,360	3,113
Retained Earnings | Progress Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	6,465	$ 7,090	$ 6,747	$ 5,715	$ 5,386	$ 5,131
Cumulative Change in Accounting Principle | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	120
Cumulative Change in Accounting Principle | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment | Duke Energy Carolinas
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	16
Cumulative Change in Accounting Principle | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment | Progress Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	2
Cumulative Change in Accounting Principle | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment | Duke Energy Progress
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	1
Cumulative Change in Accounting Principle | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment | Duke Energy Florida
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	1
Cumulative Change in Accounting Principle | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment | Piedmont Natural Gas
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings	$ 1