v2.4.0.6
Fair Value Of Financial Assets And Liabilities (Fair Value Measurement Amounts For Assets And Liabilities) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments in available-for-sale auction rate securities, fair value $ 28 [1] $ 29 [1]
Nuclear decommissioning trust fund equity securities 3,104 2,837
Nuclear decommissioning trust fund debt securities 1,432 1,405
Other long-term trading and available-for-sale equity securities 93 [2] 72 [2]
Other trading and available-for sale debt securities 634 [3] 602 [3]
Derivative assets 75 [2] 103 [2]
Assets, Fair Value Disclosure, Total 5,366 5,048
Derivative liabilities (611) [4] (756) [4]
Net Assets Fair Value, Total 4,755 4,292
Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 3,026 2,762
Nuclear decommissioning trust fund debt securities 356 317
Other long-term trading and available-for-sale equity securities 84 [2] 63 [2]
Other trading and available-for sale debt securities 94 [3] 40 [3]
Derivative assets 1 [2] 18 [2]
Assets, Fair Value Disclosure, Total 3,561 3,200
Derivative liabilities (77) [4] (17) [4]
Net Assets Fair Value, Total 3,484 3,183
Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 57 54
Nuclear decommissioning trust fund debt securities 1,027 1,040
Other long-term trading and available-for-sale equity securities 9 [2] 9 [2]
Other trading and available-for sale debt securities 540 [3] 562 [3]
Derivative assets 20 [2] 22 [2]
Assets, Fair Value Disclosure, Total 1,653 1,687
Derivative liabilities (398) [4] (591) [4]
Net Assets Fair Value, Total 1,255 1,096
Level 3 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments in available-for-sale auction rate securities, fair value 28 [1] 29 [1]
Nuclear decommissioning trust fund equity securities 21 21
Nuclear decommissioning trust fund debt securities 49 48
Derivative assets 54 [2] 63 [2]
Assets, Fair Value Disclosure, Total 152 161
Derivative liabilities (136) [4] (148) [4]
Net Assets Fair Value, Total 16 13
Duke Energy Carolinas [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments in available-for-sale auction rate securities, fair value 3 [5] 3 [5]
Nuclear decommissioning trust fund equity securities 1,734 1,592
Nuclear decommissioning trust fund debt securities 785 762
Assets, Fair Value Disclosure, Total 2,522 2,357
Derivative liabilities (5) [6] (12) [6]
Net Assets Fair Value, Total 2,517 2,345
Duke Energy Carolinas [Member] | Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 1,663 1,523
Nuclear decommissioning trust fund debt securities 180 155
Assets, Fair Value Disclosure, Total 1,843 1,678
Net Assets Fair Value, Total 1,843 1,678
Duke Energy Carolinas [Member] | Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 50 48
Nuclear decommissioning trust fund debt securities 556 559
Assets, Fair Value Disclosure, Total 606 607
Net Assets Fair Value, Total 606 607
Duke Energy Carolinas [Member] | Level 3 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments in available-for-sale auction rate securities, fair value 3 [5] 3 [5]
Nuclear decommissioning trust fund equity securities 21 21
Nuclear decommissioning trust fund debt securities 49 48
Assets, Fair Value Disclosure, Total 73 72
Derivative liabilities (5) [6] (12) [6]
Net Assets Fair Value, Total 68 60
Progress Energy [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 1,369 1,245
Nuclear decommissioning trust fund debt securities 648 643
Other trading and available-for sale debt securities 60 [7] 57 [7]
Derivative assets 15 [8] 11 [8]
Assets, Fair Value Disclosure, Total 2,092 1,956
Derivative liabilities (269) [9] (440) [9]
Net Assets Fair Value, Total 1,823 1,516
Progress Energy [Member] | Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 1,363 1,239
Nuclear decommissioning trust fund debt securities 177 162
Other trading and available-for sale debt securities 20 [7] 17 [7]
Assets, Fair Value Disclosure, Total 1,560 1,418
Net Assets Fair Value, Total 1,560 1,418
Progress Energy [Member] | Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 6 6
Nuclear decommissioning trust fund debt securities 471 481
Other trading and available-for sale debt securities 40 [7] 40 [7]
Derivative assets 15 [8] 11 [8]
Assets, Fair Value Disclosure, Total 532 538
Derivative liabilities (238) [9] (402) [9]
Net Assets Fair Value, Total 294 136
Progress Energy [Member] | Level 3 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative liabilities (31) [9] (38) [9]
Net Assets Fair Value, Total (31) (38)
Duke Energy Progress [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 894 811
Nuclear decommissioning trust fund debt securities 453 448
Other trading and available-for sale debt securities 4 [7] 3 [7]
Derivative assets 5 [8] 2 [8]
Assets, Fair Value Disclosure, Total 1,356 1,264
Derivative liabilities (98) [10] (166) [10]
Net Assets Fair Value, Total 1,258 1,098
Duke Energy Progress [Member] | Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 894 811
Nuclear decommissioning trust fund debt securities 123 119
Other trading and available-for sale debt securities 4 [7] 3 [7]
Assets, Fair Value Disclosure, Total 1,021 933
Net Assets Fair Value, Total 1,021 933
Duke Energy Progress [Member] | Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund debt securities 330 329
Derivative assets 5 [8] 2 [8]
Assets, Fair Value Disclosure, Total 335 331
Derivative liabilities (67) [10] (128) [10]
Net Assets Fair Value, Total 268 203
Duke Energy Progress [Member] | Level 3 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative liabilities (31) [10] (38) [10]
Net Assets Fair Value, Total (31) (38)
Duke Energy Florida [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 474 435
Nuclear decommissioning trust fund debt securities 196 194
Other trading and available-for sale debt securities 45 [11] 43 [11]
Derivative assets 10 [12] 9 [12]
Assets, Fair Value Disclosure, Total 725 681
Derivative liabilities (167) [13] (270) [13]
Net Assets Fair Value, Total 558 411
Duke Energy Florida [Member] | Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 468 429
Nuclear decommissioning trust fund debt securities 54 43
Other trading and available-for sale debt securities 5 [11] 3 [11]
Assets, Fair Value Disclosure, Total 527 475
Net Assets Fair Value, Total 527 475
Duke Energy Florida [Member] | Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Nuclear decommissioning trust fund equity securities 6 6
Nuclear decommissioning trust fund debt securities 142 151
Other trading and available-for sale debt securities 40 [11] 40 [11]
Derivative assets 10 [12] 9 [12]
Assets, Fair Value Disclosure, Total 198 206
Derivative liabilities (167) [13] (270) [13]
Net Assets Fair Value, Total 31 (64)
Duke Energy Ohio [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative assets 19 [14] 59 [14]
Derivative liabilities (94) [9] (38) [9]
Net Assets Fair Value, Total (75) 21
Duke Energy Ohio [Member] | Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative assets 8 [14] 48 [14]
Derivative liabilities (72) [9] (15) [9]
Net Assets Fair Value, Total (64) 33
Duke Energy Ohio [Member] | Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative assets 2 [14] 2 [14]
Derivative liabilities (8) [9] (8) [9]
Net Assets Fair Value, Total (6) (6)
Duke Energy Ohio [Member] | Level 3 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative assets 9 [14] 9 [14]
Derivative liabilities (14) [9] (15) [9]
Net Assets Fair Value, Total (5) (6)
Duke Energy Indiana [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Available-for-sale securities, equity securities, noncurrent 54 [1] 49 [1]
Available-for-sale securities, debt securities, noncurrent 29 [1] 29 [1]
Derivative assets 5 [15] 10 [15]
Assets, Fair Value Disclosure, Total 88 88
Derivative liabilities (55) [4] (63) [4]
Net Assets Fair Value, Total 33 25
Duke Energy Indiana [Member] | Level 1 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Available-for-sale securities, equity securities, noncurrent 54 [1] 49 [1]
Derivative assets 1 [15]  
Assets, Fair Value Disclosure, Total 55 49
Net Assets Fair Value, Total 55 49
Duke Energy Indiana [Member] | Level 2 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Available-for-sale securities, debt securities, noncurrent 29 [1] 29 [1]
Assets, Fair Value Disclosure, Total 29 29
Derivative liabilities (55) [4] (63) [4]
Net Assets Fair Value, Total (26) (34)
Duke Energy Indiana [Member] | Level 3 [Member]
    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative assets 4 [15] 10 [15]
Assets, Fair Value Disclosure, Total 4 10
Net Assets Fair Value, Total $ 4 $ 10
[1] Included in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets.
[2] Included in Other within Current Assets and Other within Investments and Other Assets on the Condensed Consolidated Balance Sheet.
[3] Included in Other within Investments and Other Assets and Short-term Investments on the Condensed Consolidated Balance Sheets.
[4] Included in Other within Current Liabilities and Other within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheets.
[5] Included in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheets.
[6] Included in Other within Current Liabilities and Other within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheet.
[7] Included in Other within Investments and Other Assets in the Condensed Consolidated Balance Sheets.
[8] Included in Other Current Assets within Current Assets and Other within Investments and Other Assets in the Condensed Consolidated Balance Sheets.
[9] Included in Other within Current Liabilities and Other within Deferred Credits and Other Liabilities in the Condensed Consolidated Balance Sheets.
[10] Included in Other within Current Liabilities and Other within Deferred Credits and Other Liabilities in the Condensed Consolidated Balance Sheets
[11] Included in Other within Investments and Other Assets in the Condensed Balance Sheets.
[12] Included in Other Current Assets within Current Assets and Other within Investments and Other Assets in the Condensed Balance Sheets.
[13] Included in Other within Current Liabilities and Other within Deferred Credits and Other Liabilities in the Condensed Balance Sheets
[14] Included in Other within Current Assets and Other within Investments and Other Assets in the Condensed Consolidated Balance Sheets.
[15] Included in Other within Current Assets on the Condensed Consolidated Balance Sheets.