Commitments and Contingencies Commitments and Contingencies - Legal Matters (Details) (USA Power [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 Claims
Loss Contingencies [Line Items]
Number of claims, reconsideration requested	2
Original number of claims	5
Loss Contingency, Damages Sought, Legal Fees as a Percentage of Damages	40.00%
Damages from Breach of Contract, Awarded, By Jury [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	18
Damages from Unjust Enrichment, Awarded, By Jury [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	113