Income Taxes (Deferred Income Taxes) (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		$ 382	$ 201
Capital lease obligations		60	63
Pension, postretirement and other employee benefits		561	580
Progress Energy merger purchase accounting adjustments		918	1,009
Tax credits and NOL carryforwards		4,682	3,631
Other		205	206
Valuation allowance		(96)	(93)
Total deferred income tax assets		6,712	5,597
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(1,892)	(1,573)
Accelerated depreciation rates		(14,872)	(12,939)
Regulatory assets and deferred debits, net		(4,103)	(3,633)
Total deferred income tax liabilities		(20,867)	(18,145)
Net deferred income tax liabilities		(14,155)	(12,548)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		4,682	3,631
Valuation allowance		(96)	(93)
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		(14,155)	(12,548)
State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Net reduction in deferred tax liability		80	95
Investment Tax Credits [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		1,143
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		$ 1,143
Investment Tax Credits [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2027
Investment Tax Credits [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2036
Alternative Minimum Tax Credit [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		$ 1,151
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		1,151
NOL Carryforwards [Member] | Federal [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		1,267
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		$ 1,267
NOL Carryforwards [Member] | Federal [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2020
NOL Carryforwards [Member] | Federal [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2036
NOL Carryforwards [Member] | State [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		$ 248
Valuation allowance		(84)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		248
Valuation allowance		$ (84)
NOL Carryforwards [Member] | State [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2017
NOL Carryforwards [Member] | State [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2036
NOL Carryforwards [Member] | Foreign Jurisdictions [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		$ 12
Valuation allowance		(12)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		12
Valuation allowance		$ (12)
NOL Carryforwards [Member] | Foreign Jurisdictions [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2026
NOL Carryforwards [Member] | Foreign Jurisdictions [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2036
Foreign Tax Credit [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		$ 859
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		$ 859
Foreign Tax Credit [Member] | Foreign Jurisdictions [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2024
Foreign Tax Credit [Member] | Foreign Jurisdictions [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2026
charitable carryforwards [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards		$ 2
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		$ 2
charitable carryforwards [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2017
charitable carryforwards [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year		Dec. 31, 2019
Duke Energy Carolinas [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		$ 66	38
Capital lease obligations		8	9
Pension, postretirement and other employee benefits		16	46
Tax credits and NOL carryforwards		192	170
Other		16	20
Total deferred income tax assets		298	283
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(1,149)	(1,057)
Accelerated depreciation rates		(4,664)	(4,429)
Regulatory assets and deferred debits, net		(1,029)	(943)
Total deferred income tax liabilities		(6,842)	(6,429)
Net deferred income tax liabilities		(6,544)	(6,146)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		192	170
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		(6,544)	(6,146)
Progress Energy [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		126	115
Pension, postretirement and other employee benefits		199	186
Tax credits and NOL carryforwards		1,165	997
Other		35	48
Valuation allowance		(12)	(38)
Total deferred income tax assets		1,513	1,308
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(597)	(412)
Accelerated depreciation rates		(4,490)	(4,169)
Regulatory assets and deferred debits, net		(1,672)	(1,517)
Total deferred income tax liabilities		(6,759)	(6,098)
Net deferred income tax liabilities		(5,246)	(4,790)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		1,165	997
Valuation allowance		(12)	(38)
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		(5,246)	(4,790)
Duke Energy Progress [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		40	25
Pension, postretirement and other employee benefits		91	92
Tax credits and NOL carryforwards		222	163
Other		8	2
Total deferred income tax assets		361	282
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(313)	(228)
Accelerated depreciation rates		(2,479)	(2,325)
Regulatory assets and deferred debits, net		(892)	(756)
Total deferred income tax liabilities		(3,684)	(3,309)
Net deferred income tax liabilities		(3,323)	(3,027)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		222	163
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		(3,323)	(3,027)
Duke Energy Florida [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		93	66
Pension, postretirement and other employee benefits		96	82
Tax credits and NOL carryforwards		232	177
Other			46
Total deferred income tax assets		421	371
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(297)	(201)
Accelerated depreciation rates		(2,038)	(1,868)
Regulatory assets and deferred debits, net		(780)	(762)
Total deferred income tax liabilities		(3,115)	(2,831)
Net deferred income tax liabilities		(2,694)	(2,460)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		232	177
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		(2,694)	(2,460)
Duke Energy Ohio [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		21	29
Pension, postretirement and other employee benefits		22	24
Tax credits and NOL carryforwards		49	25
Investments and other assets		3	3
Other		5	37
Total deferred income tax assets		100	118
Deferred Tax Liabilities, Gross [Abstract]
Accelerated depreciation rates		(1,404)	(1,356)
Regulatory assets and deferred debits, net		(139)	(169)
Total deferred income tax liabilities		(1,543)	(1,525)
Net deferred income tax liabilities		(1,443)	(1,407)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		49	25
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		(1,443)	(1,407)
Duke Energy Indiana [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities		4	5
Capital lease obligations		1	2
Pension, postretirement and other employee benefits		37	40
Tax credits and NOL carryforwards		278	215
Other		9	20
Total deferred income tax assets		329	282
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(21)	(7)
Accelerated depreciation rates		(1,938)	(1,797)
Regulatory assets and deferred debits, net		(270)	(135)
Total deferred income tax liabilities		(2,229)	(1,939)
Net deferred income tax liabilities		(1,900)	(1,657)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards		278	215
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Net deferred income tax liabilities		$ (1,900)	$ (1,657)
January 2015 [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate			5.00%
January 2015 [Member] | Duke Energy Carolinas [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate			5.00%
January 2015 [Member] | Duke Energy Progress [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate			5.00%
January 2016 [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate		4.00%
January 2016 [Member] | Duke Energy Carolinas [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate		4.00%
January 2016 [Member] | Duke Energy Progress [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate		4.00%
Scenario, Forecast [Member] | January 2017 [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate	3.00%
Scenario, Forecast [Member] | January 2017 [Member] | Duke Energy Carolinas [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate	3.00%
Scenario, Forecast [Member] | January 2017 [Member] | Duke Energy Progress [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Statutory Tax Rate	3.00%