Unaudited Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Statement Of Income [Line Items]
Operating revenues	$ 2,256	$ 2,372	$ 4,423	$ 4,907
Operating expenses
Fuel used in electric generation	674	743	1,392	1,639
Purchased power	329	315	549	578
Operation and maintenance	510	505	1,004	985
Depreciation, amortization and accretion	179	233	333	479
Taxes other than on income	134	133	274	287
Other	2	3	(8)	5
Total operating expenses	1,828	1,932	3,544	3,973
Operating income	428	440	879	934
Other income (expense)
Interest income	0	1	1	3
Allowance for equity funds used during construction	26	25	55	46
Other, net	7	5	10	0
Total other income, net	33	31	66	49
Interest charges
Interest charges	189	199	388	390
Allowance for borrowed funds used during construction	(9)	(7)	(18)	(16)
Total interest charges, net	180	192	370	374
Income from continuing operations before income tax	281	279	575	609
Income tax expense	101	98	208	237
Equity in earnings of consolidated subsidiaries	0	0	0	0
Income from continuing operations before cumulative effect of change in accounting principle	180	181	367	372
Discontinued operations, net of tax	(2)	(1)	(4)	0
Cumulative effect of change in accounting principle, net of tax	0	0	0	(2)
Net income	178	180	363	370
Net (income) loss attributable to noncontrolling interests, net of tax	(2)	0	(3)	0
Net income attributable to controlling interests	176	180	360	370
Average common shares outstanding - basic	296	290	295	287
Basic earnings per common share
Income from continuing operations attributable to controlling interests, net of tax	$ 0.60	$ 0.62	$ 1.23	$ 1.29
Discontinued operations attributable to controlling interests, net of tax	$ 0.00	$ 0.00	$ (0.01)	$ 0.00
Net income attributable to controlling interests	$ 0.60	$ 0.62	$ 1.22	$ 1.29
Diluted earnings per common share
Income from continuing operations attributable to controlling interests, net of tax	$ 0.60	$ 0.62	$ 1.23	$ 1.29
Discontinued operations attributable to controlling interests, net of tax	$ 0.00	$ 0.00	$ (0.01)	$ 0.00
Net income attributable to controlling interests	$ 0.60	$ 0.62	$ 1.22	$ 1.29
Dividends declared per common share	$ 0.620	$ 0.620	$ 1.240	$ 1.240
Amounts attributable to controlling interests
Income from continuing operations, net of tax	178	181	364	370
Discontinued operations, net of tax	(2)	(1)	(4)	0
Net income attributable to controlling interests	176	180	360	370
PEC
Statement Of Income [Line Items]
Operating revenues	1,060	1,117	2,193	2,380
Operating expenses
Fuel used in electric generation	326	375	689	858
Purchased power	73	76	140	126
Operation and maintenance	293	300	588	585
Depreciation, amortization and accretion	126	120	250	238
Taxes other than on income	50	51	106	111
Other	0	(1)	0	0
Total operating expenses	868	921	1,773	1,918
Operating income	192	196	420	462
Other income (expense)
Interest income	1	1	1	2
Allowance for equity funds used during construction	18	15	38	28
Other, net	1	4	(1)	(3)
Total other income, net	20	20	38	27
Interest charges
Interest charges	54	53	104	103
Allowance for borrowed funds used during construction	(6)	(5)	(11)	(9)
Total interest charges, net	48	48	93	94
Income from continuing operations before income tax	164	168	365	395
Income tax expense	57	57	127	146
Income from continuing operations before cumulative effect of change in accounting principle	107	111	238	249
Cumulative effect of change in accounting principle, net of tax	0	0	0	(2)
Net income	107	111	238	247
Net (income) loss attributable to noncontrolling interests, net of tax	0	1	0	3
Net income attributable to controlling interests	107	112	238	250
Preferred stock dividend requirement	0	0	(1)	(1)
Net income available to parent	107	112	237	249
Amounts attributable to controlling interests
Net income attributable to controlling interests	107	112	238	250
PEF
Statement Of Income [Line Items]
Operating revenues	1,193	1,252	2,225	2,522
Operating expenses
Fuel used in electric generation	348	368	703	781
Purchased power	256	239	409	452
Operation and maintenance	224	208	434	413
Depreciation, amortization and accretion	48	110	73	234
Taxes other than on income	83	83	168	176
Other	0	0	(12)	0
Total operating expenses	959	1,008	1,775	2,056
Operating income	234	244	450	466
Other income (expense)
Interest income	0	1	0	1
Allowance for equity funds used during construction	8	10	17	18
Other, net	1	1	4	3
Total other income, net	9	12	21	22
Interest charges
Interest charges	68	70	137	134
Allowance for borrowed funds used during construction	(3)	(2)	(7)	(7)
Total interest charges, net	65	68	130	127
Income from continuing operations before income tax	178	188	341	361
Income tax expense	65	69	126	140
Net income	113	119	215	221
Preferred stock dividend requirement	0	0	(1)	(1)
Net income available to parent	$ 113	$ 119	$ 214	$ 220