Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 367	$ 259
Other	197	194
Other Noncurrent Assets
Other	1	103
Total cash, cash equivalents and restricted cash	565	556	$ 641	$ 573
Progress Energy
Current Assets
Cash and cash equivalents	75	59
Other	33	39
Other Noncurrent Assets
Other		102
Total cash, cash equivalents and restricted cash	108	200	211	126
Duke Energy Florida
Current Assets
Cash and cash equivalents	22	11
Other	33	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 55	$ 50	$ 51	$ 56