Debt And Credit Facilities (Annual Maturities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 3,110		$ 1,894
2013	3,098	[1]
2014	2,196	[1]
2015	2,478	[1]
2016	2,184	[1]
2017	1,321	[1]
Thereafter	25,873	[1]
Total long-term debt, including current maturities	37,150
Duke Energy Carolinas [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	406		1,178
2013	406
2014	346
2015	506
2016	655
2017	116
Thereafter	6,712
Total long-term debt, including current maturities	8,741
Progress Energy [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	843		961
2013	843
2014	312
2015	1,262
2016	313
2017	311
Thereafter	11,387
Total long-term debt, including current maturities	14,428
Progress Energy Carolinas [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	407		502
2013	407
2014	2
2015	701
2016	2
2017	51
Thereafter	3,677
Total long-term debt, including current maturities	4,840
Progress Energy Florida [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	435		10
2013	435
2014	11
2015	561
2016	11
2017	261
Thereafter	4,041
Total long-term debt, including current maturities	5,320
Duke Energy Ohio [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	261		507
2013	261
2014	47
2015	7
2016	56
2017	2
Thereafter	1,624
Total long-term debt, including current maturities	1,997
Duke Energy Indiana [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	405		6
2013	405
2014	5
2015	5
2016	480
2017	3
Thereafter	2,804
Total long-term debt, including current maturities	3,702
Unsecured Debt [Member] | Duke Energy Corp [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	250
Interest Rate	5.65%
Unsecured Debt [Member] | Duke Energy Indiana [Member] | September 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	400
Interest Rate	5.00%
Secured Debt [Member] | March 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest Rate	3.796%
Secured Debt [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest Rate	1.009%
Secured Debt [Member] | Duke Energy Corp [Member] | March 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	423	[2]
Secured Debt [Member] | Duke Energy Corp [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	190	[3]
First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	372
First Mortgage Bonds [Member] | Duke Energy Carolinas [Member] | November 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	400
Interest Rate	5.75%
First Mortgage Bonds [Member] | Progress Energy Carolinas [Member] | September 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	400
Interest Rate	5.125%
First Mortgage Bonds [Member] | Progress Energy Florida [Member] | March 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	425
Interest Rate	4.80%
First Mortgage Bonds [Member] | Duke Energy Ohio [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 250
Interest Rate	2.10%

[1] At December 31, 2012, capital leases of Duke Energy included $158 million and $907 million of capital lease purchase accounting adjustments for Progress Energy Carolinas and Progress Energy Florida, respectively, related to power purchase agreements that are not accounted for as leases on their financial statements because of grandfathering provisions in GAAP.

[2] Represents a construction loan related to a renewable project that will be converted to a term loan once construction in complete and requirements to convert are fulfilled.

[3] Notes are fully offset with cash collateral, which is recorded in Other current assets in the Consolidated Balance Sheets as of December 31, 2012.