Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 379	$ 259
Other	210	194
Other Noncurrent Assets
Other	103	103
Total cash, cash equivalents and restricted cash	692	556	$ 1,698	$ 573
Progress Energy
Current Assets
Cash and cash equivalents	74	59
Other	13	39
Other Noncurrent Assets
Other	102	102
Total cash, cash equivalents and restricted cash	189	200	125	126
Duke Energy Florida
Current Assets
Cash and cash equivalents	22	11
Other	13	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 35	$ 50	$ 25	$ 56