XML 49 R38.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Revenue Recognition (Details) | 3 Months Ended
--- | ---
Mar. 31, 2018 | Mar. 31, 2017
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 100.00% | 100.00%
Sales Revenue, Net [Member] | Product Concentration Risk [Member] | High-Value Components [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 41.00% | 43.00%
Sales Revenue, Net [Member] | Product Concentration Risk [Member] | Standard Packaging [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 34.00% | 34.00%
Sales Revenue, Net [Member] | Product Concentration Risk [Member] | Delivery Devices [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 3.00% | 3.00%
Sales Revenue, Net [Member] | Product Concentration Risk [Member] | Contract-Manufactured Products [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 22.00% | 20.00%
Biologics [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 21.00% | 22.00%
Generics [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 21.00% | 20.00%
Pharma Customers [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 36.00% | 38.00%
Contract-Manufactured Products [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 22.00% | 20.00%
Americas [Member] | Sales Revenue, Net [Member] | Geographic Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 45.00% | 52.00%
Europe, Middle East, Africa [Member] | Sales Revenue, Net [Member] | Geographic Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 47.00% | 41.00%
Asia Pacific [Member] | Sales Revenue, Net [Member] | Geographic Concentration Risk [Member] |  |
Disaggregation of Revenue [Line Items] |  |
Percentage of net sales | 8.00% | 7.00%

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_ProductConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ProductOrServiceAxis=wst_HighValueComponentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ProductOrServiceAxis=wst_StandardPackagingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ProductOrServiceAxis=wst_DeliveryDevicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ProductOrServiceAxis=wst_ContractManufacturedProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=wst_BiologicsCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=wst_GenericsCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=wst_PharmaCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=wst_ContractManufacturedCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=us-gaap_AmericasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_GeographicConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=us-gaap_EMEAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=us-gaap_AsiaPacificMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |