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Enviromental matters (Details 2) (USD $) | 3 Months Ended
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Jun. 30, 2013
Portland Harbor Site [Member] |
Site Contingency [Line Items] |
Environmental matters investigative costs | $ 70,000,000
Eugene,OR Manufactured Gas Plant Site [Member] |
Site Contingency [Line Items] |
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
Site contingency, low estimate, loss exposure | 500,000
Bremerton, WA Manufactured Gas Plant Site [Member] |
Site Contingency [Line Items] |
Site contingency, high estimate, loss exposure | 6,400,000
Accrual for environmental loss contingencies | 12,600,000
Site contingency, low estimate, loss exposure | 340,000
Bellingham, WA Manufactured Gas Plant Site [Member] |
Site Contingency [Line Items] |
Site contingency, loss exposure not accrued, best estimate | $ 8,000,000

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- Definition The estimated proportional share of the clean-up costs. + References No definition available. + Details
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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 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 Reference 2: 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=25496072&loc=d3e14326-108349 Reference 3: 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 + Details
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- Definition Best estimate of the loss exposure for reasonably possible environmental contingencies at an individual site for which no accrual has been recorded. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 10 -Subparagraph (c),(d)(2) -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859 + Details
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