Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 853	$ 343
Other	151	170
Other Noncurrent Assets
Other	16	7
Total cash, cash equivalents and restricted cash	1,020	520	$ 692	$ 556
Duke Energy Carolinas
Current Assets
Cash and cash equivalents	4	7
Other	4
Other Noncurrent Assets
Other	1	1
Total cash, cash equivalents and restricted cash	9	8	12	21
Progress Energy
Current Assets
Cash and cash equivalents	63	70
Other	28	39
Other Noncurrent Assets
Other	4	4
Total cash, cash equivalents and restricted cash	95	113	189	200
Duke Energy Progress
Current Assets
Cash and cash equivalents	42	35
Other	13
Other Noncurrent Assets
Other	4	4
Total cash, cash equivalents and restricted cash	59	39	46	39
Duke Energy Florida
Current Assets
Cash and cash equivalents	13	23
Other	13	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 26	$ 62	$ 35	$ 50