Environmental Matters (Tables)

6 Months Ended

Jun. 30, 2015

Environmental Remediation Obligations [Abstract]

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

	Current Liabilities						Non-Current Liabilities
	June 30,				December 31,		June 30,				December 31,
In thousands	2015		2014		2014		2015		2014		2014
Portland Harbor site:
Gasco/Siltronic Sediments	$	1,512	$	799	$	1,767	$	38,342	$	38,535	$	38,019
Other Portland Harbor	1,208		1,317		1,934		4,941		3,080		4,338
Gasco site	5,938		7,152		9,535		37,031		39,553		37,117
Siltronic Uplands site	710		884		957		390		401		348
Central Service Center site	153		70		171		—		190		—
Front Street site	665		1,115		1,020		107		107		122
Oregon Steel Mills	—		—		—		179		179		179
Total	$	10,186	$	11,337	$	15,384	$	80,990	$	82,045	$	80,123

Environmental Regulatory Table [Table Text Block]

	June 30,				December 31,
In thousands	2015		2014		2014
Cumulative cash paid	$	119,403	$	108,783	$	113,740
Total regulatory asset deferral(1)	49,917		52,117		58,859