Leases (Lease Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease expense	$ 250	$ 283
Short-term lease expense	5	4
Variable lease expense	41	30
Finance lease expense
Amortization of leased assets	219	119
Interest on lease liabilities	55	61
Total finance lease expense	274	180
Total lease expense	570	497
Duke Energy Carolinas
Lessee, Lease, Description [Line Items]
Operating lease expense	43	53
Variable lease expense	17	13
Finance lease expense
Amortization of leased assets	5	8
Interest on lease liabilities	33	30
Total finance lease expense	38	38
Total lease expense	98	104
Progress Energy
Lessee, Lease, Description [Line Items]
Operating lease expense	155	162
Short-term lease expense	2	2
Variable lease expense	22	13
Finance lease expense
Amortization of leased assets	37	24
Interest on lease liabilities	48	44
Total finance lease expense	85	68
Total lease expense	264	245
Duke Energy Progress
Lessee, Lease, Description [Line Items]
Operating lease expense	83	72
Short-term lease expense	1	1
Variable lease expense	10	5
Finance lease expense
Amortization of leased assets	18	6
Interest on lease liabilities	42	37
Total finance lease expense	60	43
Total lease expense	154	121
Duke Energy Florida
Lessee, Lease, Description [Line Items]
Operating lease expense	72	90
Short-term lease expense	1	1
Variable lease expense	12	8
Finance lease expense
Amortization of leased assets	19	18
Interest on lease liabilities	6	7
Total finance lease expense	25	25
Total lease expense	110	124
Duke Energy Ohio
Lessee, Lease, Description [Line Items]
Operating lease expense	11	11
Finance lease expense
Total lease expense	11	11
Duke Energy Indiana
Lessee, Lease, Description [Line Items]
Operating lease expense	18	19
Short-term lease expense	2	1
Variable lease expense		1
Finance lease expense
Amortization of leased assets	1	1
Total finance lease expense	1	1
Total lease expense	21	22
Piedmont
Lessee, Lease, Description [Line Items]
Operating lease expense	7	7
Variable lease expense	1	1
Finance lease expense
Total lease expense	$ 8	$ 8