Environmental Matters (Tables)

9 Months Ended

Sep. 30, 2015

Environmental Remediation Obligations [Abstract]

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

	Current Liabilities						Non-Current Liabilities
	September 30,				December 31,		September 30,				December 31,
In thousands	2015		2014		2014		2015		2014		2014
Portland Harbor site:
Gasco/Siltronic Sediments	$	1,236	$	686	$	1,767	$	38,533	$	38,593	$	38,019
Other Portland Harbor	1,243		1,060		1,934		4,563		3,198		4,338
Gasco site	4,510		7,399		9,535		36,795		37,748		37,117
Siltronic Uplands site	538		634		957		489		577		348
Central Service Center site	177		70		171		—		173		—
Front Street site	420		804		1,020		215		99		122
Oregon Steel Mills	—		—		—		179		179		179
Total	$	8,124	$	10,653	$	15,384	$	80,774	$	80,567	$	80,123

Environmental Regulatory Table [Table Text Block]

	September 30,				December 31,
In thousands	2015		2014		2014
Cumulative cash paid	$	121,819	$	111,367	$	113,740
Total regulatory asset deferral(1)	49,807		51,861		58,859