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Derivative Financial Instruments (Textuals) (Details) € in Millions, ¥ in Millions, DKK in Millions, $ in Millions | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2017 USD ($) | Sep. 30, 2017 EUR (€) MBbls | Sep. 30, 2017 JPY (¥) | Sep. 30, 2017 USD ($) | Sep. 30, 2017 USD ($) MBbls | Sep. 30, 2017 DKK MBbls | Dec. 31, 2016 EUR (€) MBbls
Forward Start Interest Rate Swap [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  |  | $ 33.1 |  |
Maximum term (in years) |  | 5 years | 5 years | 5 years |  |  |
Derivative, underlying basis |  | one-month London Interbank Offered Rate (“LIBOR”) | one-month London Interbank Offered Rate (“LIBOR”) | one-month London Interbank Offered Rate (“LIBOR”) |  |  |
Fixed interest rate |  | 5.41% |  |  | 5.41% | 5.41% |
Debt EUR Denominated [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount, nonderivative instruments |  | € 21.0 |  | $ 24.8 |  |  |
Cumulative foreign currency translation gain |  |  |  |  | $ 1.0 |  |
Cumulative foreign currency translation gain, net of tax |  |  |  |  | 0.6 |  |
Debt Yen Denominated [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount, nonderivative instruments |  |  | ¥ 500.0 | 4.5 |  |  |
Cumulative foreign currency translation gain |  |  |  |  | 0.3 |  |
Cumulative foreign currency translation gain, net of tax |  |  |  |  | $ 0.2 |  |
Options Held [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Derivative, nonmonetary notional amount | MBbls |  | 17,550 |  |  | 17,550 | 17,550 | 96,525
Premium paid |  |  |  | 0.2 |  |  |
Loss related to call options | $ 0.1 |  |  | $ 0.2 |  |  |
Euro Member Countries, Euro | Forward Contracts [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount | € |  | € 72.5 |  |  |  |  | € 57.5
Denmark, Kroner | Forward Contracts [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount | DKK |  |  |  |  |  | DKK 83.4 |
Long [Member] | Designated as Hedging Instrument [Member] | Singapore, Dollars | Foreign Exchange Forward [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  |  | $ 29.9 |  |
Long [Member] | Designated as Hedging Instrument [Member] | United States of America, Dollars | Foreign Exchange Forward [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  |  | 46.3 |  |
Long [Member] | Designated as Hedging Instrument [Member] | Japan, Yen | Foreign Exchange Forward [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  |  |  |  | 5,255.3 |  |
Short [Member] | Designated as Hedging Instrument [Member] | Singapore, Dollars | Foreign Exchange Forward [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  | 6.2 |  |  | 14.6 |  |
Short [Member] | Designated as Hedging Instrument [Member] | United States of America, Dollars | Foreign Exchange Forward [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  | 41.8 |  |  | 0.0 |  |
Short [Member] | Designated as Hedging Instrument [Member] | Japan, Yen | Foreign Exchange Forward [Member] |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Notional amount |  | € 16.6 |  |  | $ 28.3 |  |

X
- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + 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 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 Reference to the index or unit of measurement for the underlying which establishes the pricing terms of the derivative instrument. For example, the basis on the underlying for a natural gas futures contract might be the NYMEX price per million British thermal units (MMBtu). + References No definition available. + Details
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- Definition Maximum period the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994 + Details
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