Debt and Credit Facilities (Annual Maturities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 2,223	$ 3,110
Other [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	373
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	717	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	11	435
Duke Energy Ohio [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	8	261
Duke Energy Indiana [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	5	405
Duke Energy Indiana [Member] | Unsecured Debt [Member] | September 2013 [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	5.00%
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%