|
Regulatory Matters (Narrative) (Details) (USD $)
|
3 Months Ended | 3 Months Ended | 3 Months Ended | 3 Months Ended | 0 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 3 Months Ended | 3 Months Ended | 3 Months Ended | |||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Dec. 31, 2012
|
Mar. 31, 2013
Duke Energy Carolinas [Member]
|
Dec. 31, 2012
Duke Energy Carolinas [Member]
|
Mar. 31, 2013
Duke Energy Carolinas [Member]
Minimum [Member]
|
Mar. 31, 2013
Duke Energy Carolinas [Member]
Maximum [Member]
|
Mar. 31, 2013
Duke Energy Carolinas [Member]
North Carolina Rate Case [Member]
|
Mar. 31, 2013
Duke Energy Carolinas [Member]
South Carolina Rate Case [Member]
|
Mar. 31, 2013
Duke Energy Carolinas [Member]
William State Lee III Nuclear Station [Member]
MW
|
Mar. 31, 2013
Duke Energy Progress [Member]
|
Dec. 31, 2012
Duke Energy Progress [Member]
|
Mar. 31, 2013
Duke Energy Progress [Member]
Plants Retired [Member]
|
Mar. 31, 2013
Duke Energy Progress [Member]
North Carolina Rate Case [Member]
|
Mar. 31, 2013
Duke Energy Progress [Member]
L V Sutton Plant [Member]
|
Mar. 31, 2013
Duke Energy Progress [Member]
Shearon Harris Nuclear Station [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
|
Dec. 31, 2012
Duke Energy Florida [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
FPSC Settlement Agreement [Member]
|
Mar. 31, 2012
Duke Energy Florida [Member]
FPSC Settlement Agreement [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
FPSC Settlement Agreement [Member]
Minimum [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
FPSC Settlement Agreement [Member]
Maximum [Member]
|
Apr. 25, 2013
Duke Energy Florida [Member]
Crystal River Unit 3 [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
Crystal River Unit 3 [Member]
|
Dec. 31, 2012
Duke Energy Florida [Member]
Crystal River Unit 3 [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
Crystal River Unit 3 [Member]
Minimum [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
Crystal River Unit 3 [Member]
Maximum [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
Levy Nuclear Station [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
Levy Nuclear Station [Member]
Minimum [Member]
|
Mar. 31, 2013
Duke Energy Florida [Member]
Levy Nuclear Station [Member]
Maximum [Member]
|
Mar. 31, 2013
Duke Energy Ohio [Member]
|
Dec. 31, 2012
Duke Energy Ohio [Member]
|
Mar. 31, 2013
Duke Energy Ohio [Member]
Ohio Electric Rate Case [Member]
|
Mar. 31, 2013
Duke Energy Ohio [Member]
Ohio Natural Gas Rate Case [Member]
|
Mar. 31, 2013
Duke Energy Ohio [Member]
RTO Realignment [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
|
Mar. 31, 2012
Duke Energy Indiana [Member]
|
Dec. 31, 2012
Duke Energy Indiana [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Plants Retired [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
|
Mar. 31, 2012
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
September 7, 2006 [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
May 1, 2008 [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
April 16, 2010 [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
June 27, 2011 [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
October 19, 2011 [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
April 30, 2012 Settlement Agreement [Member]
|
Mar. 31, 2013
Duke Energy Indiana [Member]
Edwardsport IGCC Plant [Member]
October 30, 2012 [Member]
|
|
| Plant capacity, MW | 1,117 | |||||||||||||||||||||||||||||||||||||||||||||||
| Estimated AFUDC on capital project | $ 125,000,000 | $ 160,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| Estimated capital cost of new utility plant, including AFUDC | 600,000,000 | 19,000,000,000 | 24,000,000,000 | |||||||||||||||||||||||||||||||||||||||||||||
| Percentage of completion of construction | 77.00% | |||||||||||||||||||||||||||||||||||||||||||||||
| Net property, plant and equipment | 68,813,000,000 | 68,558,000,000 | 22,964,000,000 | 22,826,000,000 | 330,000,000 | 13,179,000,000 | 13,062,000,000 | 70,000,000 | 9,513,000,000 | 9,360,000,000 | 8,139,000,000 | 8,126,000,000 | 8,373,000,000 | 8,320,000,000 | ||||||||||||||||||||||||||||||||||
| VC summer ownership percentage | 5.00% | 10.00% | ||||||||||||||||||||||||||||||||||||||||||||||
| Approved rate increase amount by state commission | 150,000,000 | 49,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| Rate increase begin date | 5/1/2013 | |||||||||||||||||||||||||||||||||||||||||||||||
| Return on equity percentage | 11.25% | 11.25% | 10.20% | 9.50% | 11.50% | 9.84% | 9.84% | |||||||||||||||||||||||||||||||||||||||||
| Average increase in retail revenues, percentage | 9.70% | 15.10% | 2.90% | |||||||||||||||||||||||||||||||||||||||||||||
| Capital structure, equity percentage | 53.00% | 53.00% | 53.00% | |||||||||||||||||||||||||||||||||||||||||||||
| Capital structure, long-term debt percentage | 47.00% | 47.00% | ||||||||||||||||||||||||||||||||||||||||||||||
| Rate Increase, Year One | 151,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Average increase in retail revenues, percentage, year one | 4.70% | |||||||||||||||||||||||||||||||||||||||||||||||
| Rate Increase, Year Two | 31,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Average increase in retail revenues, percentage, year two | 1.00% | |||||||||||||||||||||||||||||||||||||||||||||||
| Edwardsport IGCC original estimated and approved capital cost, including AFUDC | 1,985,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Edwardsport IGCC revised estimated capital cost, including AFUDC | 2,350,000,000 | 2,880,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| Edwardsport IGCC - cost cap for customers | 2,595,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Impairment charges | 0 | 402,000,000 | 0 | 400,000,000 | 897,000,000 | 420,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Edwardsport IGCC revised estimated capital costs, excluding AFUDC | 2,820,000,000 | 2,980,000,000 | 3,150,000,000 | |||||||||||||||||||||||||||||||||||||||||||||
| Edwardsport damages | 560,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Joint intervenors recommended rate disallowances | 77,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| EPA compliance capital costs | 395,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Requested rate increase amount to state commission | 446,000,000 | 220,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| Capacity rider revenues requested | 728,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| MGP remediation cost revenue requirement | 22,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| MVP project costs approved by MISO | 5,200,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Repair costs, range of possible costs | 900,000,000 | 1,300,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| NEIL coverage per company at each nuclear plant | 1,060,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Insurance deductible per claim | 10,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Future Year Four Pro Rata Replacement Power Refund | 40,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Future year five pro rata replacement power refund | 60,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Net unrecovered investment | 1,711,000,000 | 1,637,000,000 | 343,000,000 | |||||||||||||||||||||||||||||||||||||||||||||
| Public utilities cost of removal reserve reduction taken subject to regulatory order | 56,000,000 | 58,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| Public utilities, cost of removal reserve, amount subject to regulatory order | 58,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Current year customer refunds | 129,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Future year two customer refunds | 129,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Refund to customers recorded as reduction to revenue | 288,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Future year two residential and small commercial customer refunds | 10,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Future year three residential and small commercial customer refunds | 10,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Future year four residential and small commercial customer refunds | 10,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Independent review repair costs | 1,490,000,000 | 3,430,000,000 | ||||||||||||||||||||||||||||||||||||||||||||||
| Decommissioning cost study estimate | 989,000,000 | |||||||||||||||||||||||||||||||||||||||||||||||
| Total insurance proceeds received to date for Crystal River Unit 5 | 530,000,000 | 835,000,000 | 305,000,000 | |||||||||||||||||||||||||||||||||||||||||||||
| Regulatory Assets, Noncurrent | 10,778,000,000 | 11,004,000,000 | 1,707,000,000 | 1,727,000,000 | 1,791,000,000 | 1,845,000,000 | 125,000,000 | 3,243,000,000 | 3,321,000,000 | 582,000,000 | 579,000,000 | 71,000,000 | 785,000,000 | 810,000,000 | 60,000,000 | |||||||||||||||||||||||||||||||||
| Regulatory Liability, Noncurrent | $ 5,555,000,000 | $ 5,584,000,000 | $ 2,214,000,000 | $ 2,102,000,000 | $ 1,598,000,000 | $ 1,538,000,000 | $ 724,000,000 | $ 787,000,000 | $ 255,000,000 | $ 254,000,000 | $ 746,000,000 | $ 741,000,000 | ||||||||||||||||||||||||||||||||||||