Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Revenues
Regulated electric	$ 4,913	$ 5,053
Regulated natural gas	646	169
Nonregulated electric and other	170	155
Total operating revenues	5,729	5,377
Operating Expenses
Fuel used in electric generation and purchased power	1,449	1,588
Cost of natural gas	258	49
Operation, maintenance and other	1,433	1,416
Depreciation and amortization	859	793
Property and other taxes	304	295
Impairment charges		3
Total operating expenses	4,303	4,144
Gains on Sales of Other Assets and Other, net	11	7
Operating Income	1,437	1,240
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	29	8
Other income and expenses, net	86	70
Total other income and expenses	115	78
Interest Expense	491	489
Income From Continuing Operations Before Income Taxes	1,061	829
Income Tax Expense from Continuing Operations	344	252
Income from Continuing Operations	717	577
Income From Discontinued Operations, net of tax		122
Net income	717	699
Less: Net Income Attributable to Noncontrolling Interests	1	5
Net Income Attributable to Parent	716	694
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1
Reclassification into earnings from cash flow hedges	1	2
Unrealized gains on available-for-sale securities	4	4
Other Comprehensive Income, net of tax	8	41
Comprehensive Income	725	740
Less: Comprehensive Income Attributable to Noncontrolling Interests	1	6
Comprehensive Income Attributable to Parent	$ 724	$ 734
Income from continuing operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	$ 1.02	$ 0.83
Diluted (usd per share)	1.02	0.83
Income from discontinued operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)		0.18
Diluted (usd per share)		0.18
Net income attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	1.02	1.01
Diluted (usd per share)	$ 1.02	$ 1.01
Weighted average shares outstanding
Basic (shares)	700	689
Diluted (shares)	700	689
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 1,716	$ 1,740
Operating Expenses
Fuel used in electric generation and purchased power	428	421
Operation, maintenance and other	482	512
Depreciation and amortization	254	259
Property and other taxes	68	67
Total operating expenses	1,232	1,259
Operating Income	484	481
Other Income and Expenses
Other income and expenses, net	37	37
Interest Expense	103	107
Income From Continuing Operations Before Income Taxes	418	411
Income Tax Expense from Continuing Operations	148	140
Net Income Attributable to Parent	270	271
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges		1
Other Comprehensive Income, net of tax		1
Comprehensive Income Attributable to Parent	270	272
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,179	2,332
Operating Expenses
Fuel used in electric generation and purchased power	726	860
Operation, maintenance and other	544	592
Depreciation and amortization	313	290
Property and other taxes	117	119
Impairment charges		2
Total operating expenses	1,700	1,863
Gains on Sales of Other Assets and Other, net	8	6
Operating Income	487	475
Other Income and Expenses
Other income and expenses, net	24	20
Interest Expense	206	160
Income From Continuing Operations Before Income Taxes	305	335
Income Tax Expense from Continuing Operations	104	123
Net income	201	212
Less: Net Income Attributable to Noncontrolling Interests	2	3
Net Income Attributable to Parent	199	209
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1	1
Reclassification into earnings from cash flow hedges	1	1
Unrealized gains on available-for-sale securities	1	1
Other Comprehensive Income, net of tax	3	3
Comprehensive Income	204	215
Less: Comprehensive Income Attributable to Noncontrolling Interests	2	3
Comprehensive Income Attributable to Parent	202	212
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,219	1,307
Operating Expenses
Fuel used in electric generation and purchased power	364	448
Operation, maintenance and other	350	386
Depreciation and amortization	181	175
Property and other taxes	40	41
Total operating expenses	935	1,050
Gains on Sales of Other Assets and Other, net	2	1
Operating Income	286	258
Other Income and Expenses
Other income and expenses, net	19	17
Interest Expense	82	63
Income From Continuing Operations Before Income Taxes	223	212
Income Tax Expense from Continuing Operations	76	75
Net Income Attributable to Parent	147	137
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	147	137
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	959	1,024
Operating Expenses
Fuel used in electric generation and purchased power	362	412
Operation, maintenance and other	191	205
Depreciation and amortization	132	114
Property and other taxes	77	78
Impairment charges	1	2
Total operating expenses	763	811
Operating Income	196	213
Other Income and Expenses
Other income and expenses, net	16	5
Interest Expense	70	41
Income From Continuing Operations Before Income Taxes	142	177
Income Tax Expense from Continuing Operations	52	67
Net Income Attributable to Parent	90	110
Other Comprehensive Income (Loss), net of tax
Unrealized gains on available-for-sale securities	1	1
Other Comprehensive Income, net of tax	1	1
Comprehensive Income Attributable to Parent	91	111
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	337	340
Regulated natural gas	170	170
Nonregulated electric and other	11	6
Total operating revenues	518	516
Operating Expenses
Fuel used in electric generation and purchased power	97	111
Fuel used in electric generation and purchased power – nonregulated	15	10
Cost of natural gas	54	49
Operation, maintenance and other	130	119
Depreciation and amortization	67	61
Property and other taxes	72	71
Total operating expenses	435	421
Gains on Sales of Other Assets and Other, net		1
Operating Income	83	96
Other Income and Expenses
Other income and expenses, net	4	2
Interest Expense	22	20
Income From Continuing Operations Before Income Taxes	65	78
Income Tax Expense from Continuing Operations	23	21
Income from Continuing Operations	42	57
Income From Discontinued Operations, net of tax		2
Net Income Attributable to Parent	42	59
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	42	59
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	758	714
Operating Expenses
Fuel used in electric generation and purchased power	251	228
Operation, maintenance and other	174	162
Depreciation and amortization	125	125
Property and other taxes	22	23
Total operating expenses	572	538
Operating Income	186	176
Other Income and Expenses
Other income and expenses, net	8	4
Interest Expense	44	44
Income From Continuing Operations Before Income Taxes	150	136
Income Tax Expense from Continuing Operations	59	41
Net Income Attributable to Parent	91	95
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges		(1)
Other Comprehensive Income, net of tax		(1)
Comprehensive Income Attributable to Parent	91	94
Piedmont Natural Gas [Member]
Operating Revenues
Regulated natural gas	498	481
Nonregulated electric and other	2	2
Total operating revenues	500	483
Operating Expenses
Cost of natural gas	205	197
Operation, maintenance and other	77	74
Depreciation and amortization	35	34
Property and other taxes	13	11
Total operating expenses	330	316
Operating Income	170	167
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	3	16
Interest Expense	20	17
Income From Continuing Operations Before Income Taxes	153	166
Income Tax Expense from Continuing Operations	58	63
Net Income Attributable to Parent	95	103
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	$ 95	$ 103