v3.10.0.1

Derivative Financial Instruments (Narrative) (Details) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Derivative [Line Items] |  |  |  |
Debt Instrument, Face Amount |  | $ 4,300,000,000 | $ 4,550,000,000 |
Net payment on financial derivatives |  | (24,619,000) | 0 | $ 19,287,000
Energy commodity derivatives deposits |  | 37,328,000 | 0 |
Energy commodity derivatives deposits |  | 0 | 36,690,000 |
Interest Expense [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months |  | (2,200,000) |  |
4.25% Notes Due 2046 [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Debt Instrument, Face Amount |  | $ 500,000,000 | 500,000,000 |
Debt Instrument, Interest Rate, Stated Percentage |  | 4.25% |  |
Interest Rate Contract [Member] | Future Debt Issuance 2019 [Member] | Cash Flow Hedging [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  | $ 250,000,000.0 |  |
Interest Rate Contract [Member] | Future Debt Issuance 2019 [Member] | Cash Flow Hedging [Member] | Other Current Liabilities [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative Liability, Fair Value, Gross Liability |  | 8,400,000 |  |
Interest Rate Contract [Member] | Future Debt Issuance 2019 [Member] | Cash Flow Hedging [Member] | Other Current Assets [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 300,000 |  |
Interest Rate Contract [Member] | Future Debt Issuance 2018 [Member] | Cash Flow Hedging [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  | 200,000,000.0 |  |
Net payment on financial derivatives |  | $ (24,600,000) |  |
Interest Rate Contract [Member] | 4.25% Notes Due 2046 [Member] | Cash Flow Hedging [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount | $ 250,000,000.0 |  |  |
Debt Instrument, Face Amount | $ 500,000,000.0 |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 4.25% |  |  |
Net payment on financial derivatives | $ 19,300,000 |  |  |
Commodity Contract [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness |  |  | $ 2,400,000 | $ 5,200,000

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994 + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109247956&loc=SL51823488-111719 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
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- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109247956&loc=SL51823488-111719 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 + 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 Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986 + Details
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- Definition Amount of right to receive cash and securities on deposit with broker-dealers to demonstrate an intention to complete a purchase (good faith deposit) and collateral deposited by counterparty to cover the credit risk assumed (margin deposit). + References No definition available. + Details
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