Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 308	$ 311
Other	187	222
Other Noncurrent Assets
Other	105	40
Total cash, cash equivalents and restricted cash	600	573	$ 582	$ 591
Progress Energy
Current Assets
Cash and cash equivalents	70	48
Other	16	39
Other Noncurrent Assets
Other	102	39
Total cash, cash equivalents and restricted cash	188	126	136	112
Duke Energy Florida
Current Assets
Cash and cash equivalents	19	17
Other	16	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 35	$ 56	$ 40	$ 75