Debt And Credit Facilities (Annual Maturities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 3,323		$ 3,110
Secured Debt [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	190	[1]
Interest Rate	1.009%
Other [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	383
Duke Energy Carolinas [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	406		406
Duke Energy Carolinas [Member] | First Mortgage Bonds [Member] | November 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	400
Interest Rate	5.75%
Progress Energy [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	718		843
Duke Energy Progress [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	407		407
Duke Energy Progress [Member] | First Mortgage Bonds [Member] | September 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	400
Interest Rate	5.125%
Duke Energy Florida [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	10		435
Duke Energy Ohio [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	259		261
Duke Energy Ohio [Member] | First Mortgage Bonds [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	250
Interest Rate	2.10%
Duke Energy Indiana [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	405		405
Duke Energy Indiana [Member] | Unsecured Debt [Member] | September 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	400
Interest Rate	5.00%
Parent Company [Member] | Unsecured Debt [Member] | June 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	250
Interest Rate	5.65%
Parent Company [Member] | Unsecured Debt [Member] | February 2014 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	750
Interest Rate	6.30%
PGN Parent [Member] | Unsecured Debt [Member] | March 2014 [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 300
Interest Rate	6.05%

[1] Notes were fully offset with cash collateral, which was presented within Current Assets on the Condensed Consolidated Balance Sheets as of March 31, 2013 and December 31, 2012. All collateral was returned when the six-month bridge loan was replaced with a $230 million non-recourse secured credit facility issued in April 2013. See Note 2 for additional information.