Commitments And Contingencies (Details) (USD $)	1 Months Ended	3 Months Ended
	May 31, 2004	Mar. 31, 2014 hydroelectric_plant gal employee
Number Of Bargaining Unit Employees Oregon		50
Amount of Regulatory Costs Not yet Approved		$ 1,300,000
Gallons of Diesel Spilled		10,000
Percentage Of Employees, Collective Bargaining Agreement		45.00%
Majority Of Bargaining Unit Employees, Percentage		90.00%
Investigation review bid maximum (per MW)	250
Customer refund liability		200,000
Litigation Settlement, Amount		15,000,000
Number of hydroelectric plants		6
Number of years, license issued		50 years
WASHINGTON
Amount of Regulatory Costs Not yet Approved		900,000
IDAHO
Amount of Regulatory Costs Not yet Approved		$ 500,000