Environmental Matters (Tables)

12 Months Ended

Dec. 31, 2015

Environmental Remediation Obligations [Abstract]

Schedule of Environmental Loss Contingencies by Site [Table Text Block]

	Current Liabilities				Non-Current Liabilities
In thousands	2015		2014		2015		2014
Portland Harbor site:
Gasco/Siltronic Sediments	$	2,229	$	1,767	$	42,641	$	38,019
Other Portland Harbor	1,972		1,934		5,073		4,338
Gasco Upland site	10,599		9,535		52,117		37,117
Siltronic Upland site	951		957		337		348
Central Service Center site	25		171		—		—
Front Street site	1,155		1,020		7,748		122
Oregon Steel Mills	—		—		179		179
Total	$	16,931	$	15,384	$	108,095	$	80,123

Environmental Regulatory Table [Table Text Block]

In thousands	2015		2014
Cash paid	$	124,325	$	113,740
Total regulatory asset deferral(1)	85,854		58,859
Current regulatory assets(2)	9,270		—
Long-term regulatory assets	76,584		58,859