Commitments And Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments And Contingencies [Abstract]

Schedule Of Costs Of Fuel Purchased And Transported As A Percentage Of Total Fuel Costs

	2012	2011	2010
Marathon Oil Company	72.0%	44.9%	24.1%
Chevron / Unocal / Hilcorp	1.3%	16.1%	26.4%
ML&P	0.0%	3.6%	14.2%
ConocoPhillips (COP)	24.2%	31.9%	35.1%
ENSTAR	2.2%	1.3%	0.2%
Miscellaneous	0.3%	2.2%	0.0%