Business Segments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
International Energy Interest In National Methanol [Member]
Ownership interest	25.00%
Duke Energy Interest In DukeNet [Member]
Ownership interest	50.00%	100.00%
Exxon Mobil Interest In DETM [Member]
Ownership interest	40.00%
Duke Energy Interest In DETM [Member]
Ownership interest	60.00%
Alinda Capital Partners Interest In DukeNet [Member]
Ownership interest		50.00%