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Balance Sheet Components Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions | Mar. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Current Regulatory Assets [Member] |  |
Regulatory Assets and Liabilities [Line Items] |  |
Price risk management | $ 124 | $ 120
Pension and other postretirement plans | 0 | 0
Deferred income taxes | 0 | 0
Debt issuance costs | 0 | 0
Other | 7 | 9
Total regulatory assets | 131 | 129
Noncurrent Regulatory Assets [Member] |  |
Regulatory Assets and Liabilities [Line Items] |  |
Price risk management | 159 | 161
Pension and other postretirement plans | 235 | 239
Deferred income taxes | 86 | 86
Debt issuance costs | 24 | 16
Other | 22 | 22
Total regulatory assets | 526 | 524
Current Regulatory Liabilities [Member] |  |
Regulatory Assets and Liabilities [Line Items] |  |
Asset retirement removal costs | 0 | 0
Trojan decommissioning activities | 21 | 17
Asset retirement obligations | 0 | 0
Other | 36 | 38
Total regulatory liabilities | 57 | 55
Noncurrent Regulatory Liabilities [Member] |  |
Regulatory Assets and Liabilities [Line Items] |  |
Asset retirement removal costs | 850 | 837
Trojan decommissioning activities | 11 | 15
Asset retirement obligations | 46 | 45
Other | 31 | 31
Total regulatory liabilities | $ 938 | $ 928

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- Definition Regulatory assets related to price risk management activities + References No definition available. + Details
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- Definition For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences derived regulatory assets and liabilities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=51675352&loc=d3e28680-109314 + Details
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- Definition The amount for overfunded plans recognized in the balance sheet as a noncurrent asset associated with a defined benefit pension plan or other postretirement defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=21915240&loc=d3e1703-114919 + Details
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- Definition Net amount of other deferred costs capitalized at the end of the reporting period. Does not include deferred finance costs or deferred acquisition costs of insurance companies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
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- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
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