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Enviromental matters (Details 2) (USD $) | 12 Months Ended
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Dec. 31, 2012
Environmental Litigation Number 1 [Member] |
Site Contingency [Line Items] |
Site contingency, low estimate, loss exposure | $ 500,000
Site contingency, high estimate, loss exposure | 11,000,000
Estimated proportional share of cleanup liability | 50.00%
Accrual for environmental loss contingencies | 1,300,000
Environmental Litigation Number 2 [Member] |
Site Contingency [Line Items] |
Site contingency, low estimate, loss exposure | 340,000
Site contingency, high estimate, loss exposure | 6,400,000
Accrual for estimated investigative costs | 6,700,000
Accrual for environmental loss contingencies | 6,400,000
Environmental Litigation Number 3 [Member] |
Site Contingency [Line Items] |
Site contingency, loss exposure not accrued, best estimate | 8,000,000
Portland Harbor Site [Member] |
Site Contingency [Line Items] |
Estimated investigative costs (in excess of) | 70,000,000
Enviromental litigation number 4 [Member] |
Site Contingency [Line Items] |
Site contingency, loss exposure not accrued, best estimate | $ 100,000

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- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 9 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 96-1 -Paragraph 161 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14326-108349 + Details
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