XML 80 R65.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Derivative Financial Instruments (Textuals) (Details) € in Millions, ¥ in Millions, $ in Millions, $ in Millions | 12 Months Ended |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2018 USD ($) MBbls $ / bbl | Dec. 31, 2018 EUR (€) | Dec. 31, 2018 JPY (¥) | Dec. 31, 2017 USD ($) | Dec. 31, 2018 EUR (€) MBbls $ / bbl | Dec. 31, 2018 SGD ($) MBbls $ / bbl | Dec. 31, 2018 JPY (¥) MBbls $ / bbl | Apr. 24, 2018 MBbls | Dec. 31, 2017 EUR (€) | Dec. 31, 2017 SGD ($) | Nov. 22, 2017 MBbls | Oct. 02, 2017 USD ($) | Dec. 31, 2016 USD ($) | Nov. 18, 2016 MBbls
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt | $ 196.1 |  |  | $ 197.0 |  |  |  |  |  |  |  |  |  |
Forward-Start Interest Rate Swap [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount |  |  |  |  |  |  |  |  |  |  |  | $ 33.1 | $ 34.9 |
Debt Instrument, Description of Variable Rate Basis |  |  |  | one-month LIBOR |  |  |  |  |  |  |  |  |  |
Maximum term (in years) |  |  |  | 5 years |  |  |  |  |  |  |  |  |  |
Fixed interest rate |  |  |  | 5.41% |  |  |  |  | 5.41% | 5.41% |  |  |  |
Euro Note B [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cumulative foreign currency translation loss | 0.2 |  |  |  |  |  |  |  |  |  |  |  |  |
Cumulative foreign currency translation loss, net of tax | 0.1 |  |  |  |  |  |  |  |  |  |  |  |  |
Euro-Denominated Revolver [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount, nonderivative instruments | 24.0 | € 21.0 |  |  |  |  |  |  |  |  |  |  |  |
Debt Yen Denominated [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount, nonderivative instruments | 4.6 |  | ¥ 500.0 |  |  |  |  |  |  |  |  |  |  |
Cumulative foreign currency translation loss | 0.4 |  |  |  |  |  |  |  |  |  |  |  |  |
Cumulative foreign currency translation loss, net of tax | 0.3 |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity Call Options [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
(Gain) loss recorded in cost of goods and services sold, call options | $ (0.1) |  |  | $ 0.3 |  |  |  |  |  |  |  |  |  |
Commodity Call Options Held [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchased call options, barrels of crude oil (in barrels) | MBbls | 47,445 |  |  |  | 47,445 | 47,445 | 47,445 | 30,612 |  |  | 125,166 |  |  | 96,525
Derivative, Average Price Risk Option Strike Price | $ / bbl | 76.45 |  |  |  | 76.45 | 76.45 | 76.45 |  |  |  |  |  |  |
Euro Member Countries, Euro | Forward Contracts [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | € |  |  |  |  | € 10.0 |  |  |  | € 12.0 |  |  |  |  |
United States of America, Dollars | Forward Contracts [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | $ 13.4 |  |  | $ 13.4 |  |  |  |  |  |  |  |  |  |
United States of America, Dollars | Long [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | 32.9 |  |  |  |  |  |  |  |  |  |  |  |  |
United States of America, Dollars | Short [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | 0.0 |  |  |  | 27.8 |  |  |  |  |  |  |  |  |
Japan, Yen | Long [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | ¥ |  |  |  |  |  |  | ¥ 5,602.7 |  |  |  |  |  |  |
Japan, Yen | Short [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | 27.3 |  |  |  | 20.4 |  |  |  |  |  |  |  |  |
Singapore, Dollars | Forward Contracts [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount |  |  |  |  |  | $ 601.5 |  |  |  | $ 171.0 |  |  |  |
Singapore, Dollars | Long [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount |  |  |  |  |  | $ 42.4 |  |  |  |  |  |  |  |
Singapore, Dollars | Short [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | $ 20.0 |  |  |  | € 9.5 |  |  |  |  |  |  |  |  |

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
Name: | invest_DerivativeNonmonetaryNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- 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
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The average strike price on the group of price risk option contracts such as put options or call options. + References No definition available. + Details
Name: | us-gaap_DerivativeAveragePriceRiskOptionStrikePrice
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fixed interest rate related to the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) recognized in earnings in the period from the increase (decrease) in fair value of price risk derivatives not designated as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
Name: | us-gaap_GainLossOnPriceRiskDerivativeInstrumentsNotDesignatedAsHedgingInstruments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: 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)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994 + Details
Name: | us-gaap_MaximumLengthOfTimeHedgedInInterestRateCashFlowHedge1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payments on a nonderivative instrument. + References No definition available. + Details
Name: | us-gaap_NotionalAmountOfNonderivativeInstruments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after tax, of cumulative translation adjustment attributable to gain (loss) on foreign currency derivatives that are designated as, and are effective as, economic hedges of a net investment in a foreign entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109240241&loc=d3e32211-110900 + Details
Name: | us-gaap_TranslationAdjustmentForNetInvestmentHedgeNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Pre-tax cumulative adjustment resulting from gains and losses on foreign currency derivatives that are designated as, and are effective as, hedges of a net investment in a foreign entity, commencing as of the designation date. Adjustment reported in equity as part of accumulated other comprehensive income. + References No definition available. + Details
Name: | wst_TranslationAdjustmentForNetInvestmentHedgePreTax
Namespace Prefix: | wst_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wst_ForwardStartInterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_DebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wst_EuroDenominatedRevolverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wst_DebtYenDenominatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_OptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_USD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeForwardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_JPY
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_SGD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |