Environmental Matters (details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Mar. 31, 2014	Jun. 30, 2014		Dec. 31, 2013		Jun. 30, 2013
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	$ 82,045,000			$ 82,045,000		$ 81,895,000		$ 49,973,000
Environmental Current Liabilities	11,337,000			11,337,000		16,176,000		14,581,000
Environmental Regulatory Table [Abstract]
Cash Paid for Environmental Sites	108,783,000	[1]		108,783,000	[1]	98,817,000	[1]	83,936,000	[1]
Regulatory Assets, Noncurrent	267,248,000			267,248,000		369,603,000		393,652,000
Environmental Remediation Obligations [Abstract]
Damages Sought On Environmental Claims				50,000,000
Environmental Settlement Insurance Payments Expected in 2014			102,000,000
Portland Harbor draft FS range				$169 million to $1.8 billion
Portland Harbor Number Of Potentially Responsible Parties				more than 100
Gasco Siltronic Sediments draft EE/CA range				$39.3 million to $350 million
Gasco Siltronic Sediments Project Liability	39,300,000.0			39,300,000.0
Gasco Groundwater Source Control construction costs				19,000,000
Gasco Groundwater Source Control Allocated Insurance Proceeds To Constructed Water Treatment Station	2,500,000
Gasco Siltronic Sediments [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	38,535,000			38,535,000		37,954,000		38,058,000
Environmental Current Liabilities	799,000			799,000		1,278,000		427,000
Portland Harbor Other [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	3,080,000			3,080,000		3,478,000		2,598,000
Environmental Current Liabilities	1,317,000			1,317,000		1,766,000		1,729,000
Gasco Upland [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	39,553,000			39,553,000		39,508,000		8,230,000
Environmental Current Liabilities	7,152,000			7,152,000		11,010,000		11,354,000
Siltronic Upland [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	401,000			401,000		406,000		392,000
Environmental Current Liabilities	884,000			884,000		763,000		496,000
Central Service Center [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	190,000			190,000		248,000		338,000
Environmental Current Liabilities	70,000			70,000		85,000		100,000
Front Street [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	107,000			107,000		122,000		178,000
Environmental Current Liabilities	1,115,000			1,115,000		1,274,000		475,000
Oregon Steel Mills [Member]
Accrual for Environmental Loss Contingencies [Abstract]
Environmental Noncurrent Liabilities	179,000			179,000		179,000		179,000
Environmental Current Liabilities	0			0		0		0
Environmental Restoration Costs [Member]
Environmental Regulatory Table [Abstract]
Regulatory Assets, Noncurrent	$ 52,117,000	[2],[3]		$ 52,117,000	[2],[3]	$ 148,389,000	[2],[3]	$ 120,224,000	[2],[3]

[1] Includes $20.3 million reclassified to utility plant in 2013 associated with the water treatment station of which a portion was paid in 2012-2014.

[2] Environmental costs relate to specific sites approved for regulatory deferral by the Public Utility Commission of Oregon (OPUC) and Washington Utilities and Transportation Commission (WUTC). In Oregon, we earn a carrying charge on cash amounts paid, whereas amounts accrued but not yet paid do not earn a carrying charge until expended. In Washington, a carrying charge related to deferred amounts will be determined in a future proceeding. For further information on environmental matters, see Note 13.

[3] Includes cash paid, remaining liability, and interest, net of insurance reimbursement and amounts reclassified to utility plant for the water treatment station.