Income Tax (details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Expense [Abstract]
Income tax charge from increased effective Oregon tax rate			$ 0.6
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	728,000	1,330,000	26,449,000	26,569,000
Differences Required To Be Flowed Through By Regulatory Commissions	61,000	52,000	1,494,000	1,564,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	(9,000)	(44,000)	(178,000)	(835,000)
Income Tax Expense (Benefit)	$ 780,000	$ 1,338,000	$ 27,765,000	$ 27,298,000
Effective Income Tax Rate	42.10%	38.60%	41.60%	40.70%