Commitments and Contingencies Commitments and Contingencies (Details) (USD $)	1 Months Ended		12 Months Ended
	Mar. 31, 2007 family	May 31, 2004	Dec. 31, 2013 hydroelectric_plant employee agreement	Jun. 30, 2013	Mar. 30, 2007	Jun. 30, 2005
Loss Contingencies [Line Items]
Investigation Reviewing		$ 250
Customer Refund Liability, Current			200,000
Litigation Settlement, Amount			15,000,000
Number Of Families That Own Property Near The Holding Ponds Who Filed A Complaint	2
Owners percentage interest			15.00%		15.00%
Accrual for Environmental Loss Contingencies, Component Amount				100,000		500,000
Number Of Hydroelectric Plants			6
Number Of Years, License Issued			50 years
Amount of Regulatory Costs Not yet Approved			4,597,000
Percentage Of Employees, Collective Bargaining Agreement			45.00%
Majority Of Bargaining Unit Employees, Percentage			90.00%
Number of Collective Bargaining Agreements			2
Number Of Employees Covering Two Agreements			50
River Relicensing Expense [Member]
Loss Contingencies [Line Items]
Amount of Regulatory Costs Not yet Approved			1,300,000
WASHINGTON | River Relicensing Expense [Member]
Loss Contingencies [Line Items]
Amount of Regulatory Costs Not yet Approved			900,000
IDAHO | River Relicensing Expense [Member]
Loss Contingencies [Line Items]
Amount of Regulatory Costs Not yet Approved			$ 500,000