Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Operating Revenues
Regulated electric	$ 2,775	$ 2,743	$ 7,135	$ 7,161
Non-regulated electric and other	13	10	43	35
Total operating revenues	2,788	2,753	7,178	7,196
Operating expenses
Fuel used in electric generation and purchased power	1,396	1,234	3,299	3,186
Operation, maintenance and other	626	494	1,798	1,500
Depreciation and amortization	174	175	571	508
Property and other taxes	160	164	440	437
Impairment charges	55	0	55	0
Total operating expenses	2,411	2,067	6,163	5,631
Gains on sales of other assets and other, net	2	1	4	2
Operating income	379	687	1,019	1,567
Other income and expenses, net	32	(44)	97	21
Interest expense, net	182	172	560	542
Income from continuing operations before income taxes	229	471	556	1,046
Income tax expense from continuing operations	75	178	193	386
Income from continuing operations	154	293	363	660
Income (loss) from discontinued operations, net of tax	3	0	10	(4)
Net income	157	293	373	656
Less: net income attributable to noncontrolling interests	2	2	5	5
Net income attributable to Duke Energy Corporation	155	291	368	651
Net income amounts attributable to Duke Energy Corporation
Income from continuing operations, net of tax	152	291	358	655
Discontinued operations, net of tax	3	0	10	(4)
Net income attributable to Duke Energy Corporation	155	291	368	651
Comprehensive income, net of tax
Comprehensive income	255	228	472	574
Comprehensive income attributable to noncontrolling interests, net of tax	(2)	(2)	(5)	(5)
Comprehensive income attributable to Duke Energy Corporation	253	226	467	569
PEC [Member]
Operating Revenues
Regulated electric	1,394	1,330	3,561	3,524
Non-regulated electric and other	4	1	17	10
Total operating revenues	1,398	1,331	3,578	3,534
Operating expenses
Fuel used in electric generation and purchased power	597	544	1,450	1,382
Operation, maintenance and other	384	273	1,146	863
Depreciation and amortization	131	132	399	383
Property and other taxes	60	58	168	164
Impairment charges	55	0	55	0
Total operating expenses	1,227	1,007	3,218	2,792
Gains on sales of other assets and other, net	1	0	2	1
Operating income	172	324	362	743
Other income and expenses, net	21	16	57	55
Interest expense, net	52	41	156	134
Income from continuing operations before income taxes	141	299	263	664
Income tax expense from continuing operations	45	100	83	227
Net income	96	199	180	437
Less: preferred stock dividend requirement	1	1	2	2
Net income available to parent	95	198	178	435
Comprehensive income, net of tax
Comprehensive income attributable to Duke Energy Corporation	168	165	251	400
PEF [Member]
Operating Revenues
Regulated electric	1,382	1,414	3,576	3,639
Non-regulated electric and other	6	5	18	16
Total operating revenues	1,388	1,419	3,594	3,655
Operating expenses
Fuel used in electric generation and purchased power	799	690	1,849	1,804
Operation, maintenance and other	245	222	660	652
Depreciation and amortization	39	39	158	112
Property and other taxes	99	106	271	274
Total operating expenses	1,182	1,057	2,938	2,842
Gains on sales of other assets and other, net	1	1	2	2
Operating income	207	363	658	815
Other income and expenses, net	11	5	29	24
Interest expense, net	62	46	194	176
Income from continuing operations before income taxes	156	322	493	663
Income tax expense from continuing operations	56	119	182	245
Net income	100	203	311	418
Less: preferred stock dividend requirement	0	0	1	1
Net income available to parent	100	203	310	417
Comprehensive income, net of tax
Comprehensive income attributable to Duke Energy Corporation	$ 126	$ 186	$ 337	$ 396