v3.3.0.814

Regulatory Matters (Narrative) (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Mar. 31, 2017 USD ($) | Sep. 30, 2015 USD ($) | Sep. 30, 2014 USD ($) | Sep. 30, 2015 USD ($) MW | Sep. 30, 2014 USD ($) | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($)
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Electric Domestic Regulated Revenue |  | $ (6,017,000,000) | $ (5,861,000,000) | $ (16,564,000,000) | $ (16,549,000,000) |  |
Regulatory assets, noncurrent |  | 11,290,000,000 |  | 11,290,000,000 |  |  | $ 11,042,000,000
Impairment charges |  | 111,000,000 | 1,000,000 | 111,000,000 | 81,000,000 |  |
Other Nonoperating Income (Expense) |  | (57,000,000) | (109,000,000) | (203,000,000) | (293,000,000) |  |
Payments to Acquire Businesses, Gross |  |  |  | 1,317,000,000 | 16,000,000 |  |
Property, Plant and Equipment, Net |  | 73,776,000,000 |  | 73,776,000,000 |  |  | 70,046,000,000
Payments to Acquire Property, Plant, and Equipment |  |  |  | 4,642,000,000 | 3,755,000,000 |  |
Other liabilities |  | 1,595,000,000 |  | 1,595,000,000 |  |  | 1,675,000,000
Accounts Payable, Current |  | $ 2,078,000,000 |  | $ 2,078,000,000 |  |  | 2,271,000,000
Atlantic Coast Pipeline (ACP) [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 40.00% |  | 40.00% |  |  |
Atlantic Coast Pipeline (ACP) [Member] | Dominion Resources [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 45.00% |  | 45.00% |  |  |
Atlantic Coast Pipeline (ACP) [Member] | Piedmont Natural Gas [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 10.00% |  | 10.00% |  |  |
Sabal Trail Transmission Pipeline [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 7.50% |  | 7.50% |  |  |
Sabal Trail Transmission Pipeline [Member] | Spectra Energy [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 59.50% |  | 59.50% |  |  |
Sabal Trail Transmission Pipeline [Member] | NextEra [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 33.00% |  | 33.00% |  |  |
Generation Facilities To Be Retired [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Capacity (in MW) | MW |  |  |  | 1,541 |  |  |
Property, Plant and Equipment, Net |  | $ 207,000,000 |  | $ 207,000,000 |  |  |
Duke Energy Carolinas [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Regulatory assets, noncurrent |  | 2,741,000,000 |  | 2,741,000,000 |  |  | 2,465,000,000
Impairment charges |  |  |  |  | 3,000,000 |  |
Other Nonoperating Income (Expense) |  | (42,000,000) | (44,000,000) | (125,000,000) | (137,000,000) |  |
Property, Plant and Equipment, Net |  | 25,208,000,000 |  | 25,208,000,000 |  |  | 24,672,000,000
Payments to Acquire Property, Plant, and Equipment |  |  |  | 1,372,000,000 | 1,289,000,000 |  |
Other liabilities |  | 618,000,000 |  | 618,000,000 |  |  | 642,000,000
Accounts Payable, Current |  | 623,000,000 |  | 623,000,000 |  |  | 709,000,000
Duke Energy Carolinas [Member] | William States Lee Combined Cycle Facility [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Estimated capital cost of new utility plant, including AFUDC |  | $ 600,000,000 |  | $ 600,000,000 |  |  |
Duke Energy Carolinas [Member] | William States Lee Combined Cycle Facility [Member] | NCEMC [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 13.00% |  | 13.00% |  |  |
Duke Energy Carolinas [Member] | Generation Facilities To Be Retired [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Property, Plant and Equipment, Net |  | $ 110,000,000 |  | $ 110,000,000 |  |  |
Duke Energy Progress [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Regulatory assets, noncurrent |  | 2,816,000,000 |  | 2,816,000,000 |  |  | 2,675,000,000
Impairment charges |  |  |  |  | (18,000,000) |  |
Other Nonoperating Income (Expense) |  | (14,000,000) | (18,000,000) | (49,000,000) | (34,000,000) |  |
Payments to Acquire Businesses, Gross |  |  |  | 1,249,000,000 |  |  |
Property, Plant and Equipment, Net |  | 17,172,000,000 |  | 17,172,000,000 |  |  | 15,186,000,000
Payments to Acquire Property, Plant, and Equipment |  |  |  | 1,120,000,000 | 871,000,000 |  |
Other liabilities |  | 120,000,000 |  | 120,000,000 |  |  | 168,000,000
Accounts Payable, Current |  | 381,000,000 |  | 381,000,000 |  |  | 481,000,000
Duke Energy Progress [Member] | Western Carolinas Modernization Plan [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Estimated capital cost |  | 1,100,000,000 |  | $ 1,100,000,000 |  |  |
Duke Energy Progress [Member] | Generation Facilities To Be Retired [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Capacity (in MW) | MW |  |  |  | 376 |  |  |
Property, Plant and Equipment, Net |  | 460,000,000 |  | $ 460,000,000 |  |  |
Duke Energy Florida [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Regulatory assets, noncurrent |  | 2,719,000,000 |  | 2,719,000,000 |  |  | 2,733,000,000
Impairment charges |  | 7,000,000 | 1,000,000 | 7,000,000 | 2,000,000 |  |
Other Nonoperating Income (Expense) |  | (2,000,000) | (6,000,000) | (12,000,000) | (17,000,000) |  |
Property, Plant and Equipment, Net |  | 10,363,000,000 |  | 10,363,000,000 |  |  | 9,955,000,000
Payments to Acquire Property, Plant, and Equipment |  |  |  | 696,000,000 | 513,000,000 |  |
Other liabilities |  | 157,000,000 |  | 157,000,000 |  |  | 158,000,000
Accounts Payable, Current |  | 316,000,000 |  | $ 316,000,000 |  |  | 365,000,000
Duke Energy Florida [Member] | Scenario, Forecast [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross | $ 166,000,000 |  |  |  |  |  |
Duke Energy Florida [Member] | FERC Transmission Rates [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Public Utilities, Requested Return on Equity, Percentage |  |  |  | 10.00% |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 10.80% |  |  |
Customer Refund Liability, Noncurrent |  | 14,100,000 |  | $ 14,100,000 |  |  |
Duke Energy Florida [Member] | FERC Complaint 3 [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 8.69% |  |  |
Duke Energy Florida [Member] | Citrus County Station [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Estimated capital cost of new utility plant, including AFUDC |  | 1,500,000,000 |  | $ 1,500,000,000 |  |  |
Duke Energy Florida [Member] | Suwannee Station [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Estimated capital cost of new utility plant, including AFUDC |  | 197,000,000 |  | 197,000,000 |  |  |
Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement[Member] | FPSC [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Impairment charges |  | 15,000,000 |  |  |  |  |
Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement[Member] | FPSC [Member] | Scenario, Forecast [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Amount of Regulatory Costs Not yet Approved |  |  |  |  |  | $ 1,298,000,000 |
Regulatory assets, noncurrent |  |  |  |  |  | 1,283,000,000 |
Approved rate increase amount by state commission |  |  |  |  |  | 168,000,000 |
Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | Crystal River Unit 3 Requested Financing Order [Member] | FPSC [Member] | Scenario, Forecast [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  |  |  |  | $ 93,000,000 |
Duke Energy Florida [Member] | Levy Nuclear Station [Member] | FPSC [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Regulatory assets, noncurrent |  | 54,000,000 |  | 54,000,000 |  |  |
Approved rate increase amount by state commission |  |  |  | $ 0 |  |  |
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Capacity (in MW) | MW |  |  |  | 873 |  |  |
Property, Plant and Equipment, Net |  | 121,000,000 |  | $ 121,000,000 |  |  |
Duke Energy Ohio [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Electric Domestic Regulated Revenue |  | (367,000,000) | (352,000,000) | (1,005,000,000) | (998,000,000) |  |
Regulatory assets, noncurrent |  | 495,000,000 |  | 495,000,000 |  |  | 512,000,000
Impairment charges |  |  |  |  | 94,000,000 |  |
Other Nonoperating Income (Expense) |  |  | (3,000,000) | 2,000,000 | (9,000,000) |  |
Property, Plant and Equipment, Net |  | 5,175,000,000 |  | 5,175,000,000 |  |  | 4,937,000,000
Payments to Acquire Property, Plant, and Equipment |  |  |  | 266,000,000 | 242,000,000 |  |
Other liabilities |  | 165,000,000 |  | 165,000,000 |  |  | 166,000,000
Accounts Payable, Current |  | $ 219,000,000 |  | 219,000,000 |  |  | 209,000,000
Duke Energy Ohio [Member] | EE and Peak Demand Reduction Program [Member] | PUCO [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Electric Domestic Regulated Revenue |  |  |  | $ 23,000,000 |  |  |
Duke Energy Ohio [Member] | Natural Gas Rate Case [Member] | PUCO [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 9.84% |  |  |
Duke Energy Ohio [Member] | MGP Remediation [Member] | PUCO [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved rate increase amount by state commission |  |  |  | $ 56,000,000 |  |  |
Duke Energy Ohio [Member] | FERC Complaint 1 [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 11.38% |  |  |
Duke Energy Ohio [Member] | FERC Transmission Rates [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 12.38% |  |  |
Percentage Recovered Through Future Rate Case |  |  |  | 30.00% |  |  |
Duke Energy Ohio [Member] | RTO Realignment [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved MVP Proposals |  | 17 |  | 17 |  |  |
MISO estimate of Duke Energy Ohio's MVP obligation |  |  |  | $ 2,700,000,000 |  |  |
Duke Energy Ohio [Member] | East Bend Station [Member] | Dayton Power and Light [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Joint owner ownership percentage |  | 31.00% |  | 31.00% |  |  |
Payments to Acquire Property, Plant, and Equipment |  |  |  | $ 12,400,000 |  |  |
Duke Energy Ohio [Member] | Regional Transmission Organization [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Restructuring Reserve |  | $ 91,000,000 |  | 91,000,000 |  |  |
Regulatory assets, noncurrent |  | 72,000,000 |  | 72,000,000 |  |  |
Duke Energy Indiana [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Regulatory assets, noncurrent |  | 645,000,000 |  | 645,000,000 |  |  | 685,000,000
Impairment charges |  | 85,000,000 |  | 85,000,000 |  |  |
Other Nonoperating Income (Expense) |  |  | $ (5,000,000) | (9,000,000) | (16,000,000) |  |
Property, Plant and Equipment, Net |  | 9,340,000,000 |  | 9,340,000,000 |  |  | 8,815,000,000
Payments to Acquire Property, Plant, and Equipment |  |  |  | 506,000,000 | $ 462,000,000 |  |
Other liabilities |  | 107,000,000 |  | 107,000,000 |  |  | 90,000,000
Accounts Payable, Current |  | 149,000,000 |  | $ 149,000,000 |  |  | $ 179,000,000
Duke Energy Indiana [Member] | FERC Transmission Rates [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 12.38% |  |  |
Duke Energy Indiana [Member] | FERC Transmission Rates [Member] | Federal Energy Regulatory Commission [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 0.50% |  |  |
Duke Energy Indiana [Member] | FERC Complaint 2 [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Approved return on equity percentage amount by state commission |  |  |  | 8.67% |  |  |
Duke Energy Indiana [Member] | Grid Infrastructure Improvement Plan [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Estimated capital cost |  | 1,900,000,000 |  | $ 1,900,000,000 |  |  |
Duke Energy Indiana [Member] | Edwardsport Igcc Plant [Member] | IGCC Rider Proceeding [Member] | IURC [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  |  | (7,000,000) |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount |  |  |  | 78,000,000 |  |  |
Legal Fees |  |  |  | 5,000,000 |  |  |
Impairment charges |  |  |  | 85,000,000 |  |  |
Other Nonoperating Income (Expense) |  |  |  | 5,000,000 |  |  |
Amount of Impairment to Carrying Amount of Regulatory Assets |  | 78,000,000 |  | 78,000,000 |  |  |
Other liabilities |  | 7,000,000 |  | 7,000,000 |  |  |
Accounts Payable, Current |  | 5,000,000 |  | $ 5,000,000 |  |  |
Regulatory Asset, Amortization Period |  |  |  | 8 years |  |  |
Regulatory Assets |  | 108,000,000 |  | $ 108,000,000 |  |  |
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member] |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |
Capacity (in MW) | MW |  |  |  | 668 |  |  |
Property, Plant and Equipment, Net |  | $ 86,000,000 |  | $ 86,000,000 |  |  |

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