$WST
WEST PHARMACEUTICAL SERVICES INC Stock $wst

$wst Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000010577021000008 Filed on February 23, 2021

Income Statement

Concept	2020 Q4	2019 Q4	2019 Q3
Revenue	$580.2M	$470.6M	$456.1M
YoY Change	23.29%	11.38%	5.65%
Cost Of Revenue	$369.1M	$317.4M	$308.3M
YoY Change	16.29%	9.71%	4.12%
Gross Profit	$211.1M	$153.2M	$147.8M
YoY Change	37.79%	15.02%	9.0%
Gross Profit Margin	36.38%	32.55%	32.41%
Selling, General & Admin	$76.30M	$69.00M	$64.80M
YoY Change	10.58%	15.58%	-0.15%
% of Gross Profit	36.14%	45.04%	43.84%
Research & Development	$12.90M	$10.20M	$9.300M
YoY Change	26.47%	4.08%	-7.92%
% of Gross Profit	6.11%	6.66%	6.29%
Depreciation & Amortization	$28.50M	$26.30M	$25.30M
YoY Change	8.37%	0.0%	-3.44%
% of Gross Profit	13.5%	17.17%	17.12%
Operating Expenses	$91.40M	$74.00M	$74.10M
YoY Change	23.51%	13.85%	-1.2%
Operating Profit	$119.7M	$79.20M	$67.30M
YoY Change	51.14%	16.13%	10.69%
Interest Expense	-$4.900M	-$800.0K	$2.100M
YoY Change	512.5%	-50.0%	5.0%
% of Operating Profit	-4.09%	-1.01%	3.12%
Other Income/Expense, Net	$900.0K	$100.0K	-$1.300M
YoY Change	800.0%	-93.75%	-172.22%
Pretax Income	$115.1M	$77.40M	$64.90M
YoY Change	48.71%	17.63%	6.22%
Income Tax	$20.40M	$16.50M	$10.90M
% Of Pretax Income	17.72%	21.32%	16.8%
Net Earnings	$98.40M	$63.90M	$56.30M
YoY Change	53.99%	22.88%	1.99%
Net Earnings / Revenue	16.96%	13.58%	12.34%
Basic Earnings Per Share	$1.32	$0.86	$0.76
Diluted Earnings Per Share	$1.29	$0.84	$0.75
COMMON SHARES
Basic Shares Outstanding	73.93M shares		74.00M shares
Diluted Shares Outstanding			75.50M shares

Balance Sheet

Concept	2020 Q4	2019 Q4	2019 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$615.5M	$439.1M	$396.0M
YoY Change	40.17%	30.14%	33.2%
Cash & Equivalents	$615.5M	$439.1M	$396.0M
Short-Term Investments
Other Short-Term Assets	$51.60M	$64.60M	$61.60M
YoY Change	-20.12%	18.97%	42.92%
Inventory	$321.3M	$235.7M	$230.4M
Prepaid Expenses
Receivables	$385.3M	$319.3M	$316.1M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$1.374B	$1.059B	$1.004B
YoY Change	29.75%	18.37%	18.12%
LONG-TERM ASSETS
Property, Plant & Equipment	$943.2M	$839.3M	$812.1M
YoY Change	12.38%	2.1%	-1.2%
Goodwill	$111.1M	$107.8M	$106.6M
YoY Change	3.06%	1.89%	0.28%
Intangibles	$30.50M	$29.80M	$28.70M
YoY Change	2.35%	46.8%	36.67%
Long-Term Investments	$201.9M	$179.3M	$84.00M
YoY Change	12.6%	130.46%	8.95%
Other Assets	$23.40M	$24.70M	$20.00M
YoY Change	-5.26%	20.49%	-7.83%
Total Long-Term Assets	$1.420B	$1.283B	$1.170B
YoY Change	10.71%	18.28%	6.74%
TOTAL ASSETS
Total Short-Term Assets	$1.374B	$1.059B	$1.004B
Total Long-Term Assets	$1.420B	$1.283B	$1.170B
Total Assets	$2.794B	$2.341B	$2.174B
YoY Change	19.32%	18.32%	11.71%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$213.1M	$156.8M	$145.3M
YoY Change	35.91%	20.25%	16.05%
Accrued Expenses	$118.4M	$84.80M	$84.60M
YoY Change	39.62%	26.95%	21.73%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$2.300M	$2.300M	$0.00
YoY Change	0.0%	2200.0%
Total Short-Term Liabilities	$503.4M	$341.6M	$335.0M
YoY Change	47.37%	20.41%	16.0%
LONG-TERM LIABILITIES
Long-Term Debt	$252.9M	$255.0M	$195.1M
YoY Change	-0.82%	30.1%	-0.56%
Other Long-Term Liabilities	$31.80M	$23.40M	$35.70M
YoY Change	35.9%	-30.36%	-18.49%
Total Long-Term Liabilities	$284.7M	$278.4M	$230.8M
YoY Change	2.26%	21.25%	-3.83%
TOTAL LIABILITIES
Total Short-Term Liabilities	$503.4M	$341.6M	$335.0M
Total Long-Term Liabilities	$284.7M	$278.4M	$230.8M
Total Liabilities	$939.3M	$768.2M	$686.4M
YoY Change	22.27%	31.86%	15.5%
SHAREHOLDERS EQUITY
Retained Earnings	$1.847B	$1.549B	$1.497B
YoY Change	19.19%	14.48%	14.06%
Common Stock	$18.80M	$18.80M	$18.80M
YoY Change	0.0%	0.0%	0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$167.7M	$118.1M	$126.6M
YoY Change	42.0%	13.89%	16.47%
Treasury Stock Shares	1.300M shares	1.200M shares	1.300M shares
Shareholders Equity	$1.855B	$1.573B	$1.488B
YoY Change
Total Liabilities & Shareholders Equity	$2.794B	$2.341B	$2.174B
YoY Change	19.32%	18.32%	11.71%

Cashflow Statement

Concept	2020 Q4	2019 Q4	2019 Q3
OPERATING ACTIVITIES
Net Income	$98.40M	$63.90M	$56.30M
YoY Change	53.99%	22.88%	1.99%
Depreciation, Depletion And Amortization	$28.50M	$26.30M	$25.30M
YoY Change	8.37%	0.0%	-3.44%
Cash From Operating Activities	$148.7M	$106.4M	$108.1M
YoY Change	39.76%	45.36%	22.29%
INVESTING ACTIVITIES
Capital Expenditures	$53.90M	$37.60M	$31.70M
YoY Change	43.35%	25.33%	19.62%
Acquisitions
YoY Change
Other Investing Activities	-$3.700M	-$83.00M	$100.0K
YoY Change	-95.54%	-6028.57%
Cash From Investing Activities	-$57.60M	-$120.6M	-$31.60M
YoY Change	-52.24%	321.68%	19.25%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-8.700M	51.00M	-400.0K
YoY Change	-117.06%	-721.95%	-103.96%
NET CHANGE
Cash From Operating Activities	148.7M	106.4M	108.1M
Cash From Investing Activities	-57.60M	-120.6M	-31.60M
Cash From Financing Activities	-8.700M	51.00M	-400.0K
Net Change In Cash	82.40M	36.80M	76.10M
YoY Change	123.91%	1.1%	5.69%
FREE CASH FLOW
Cash From Operating Activities	$148.7M	$106.4M	$108.1M
Capital Expenditures	$53.90M	$37.60M	$31.70M
Free Cash Flow	$94.80M	$68.80M	$76.40M
YoY Change	37.79%	59.26%	23.42%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0000105770
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2017	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201409Member
CY2019	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201613Member
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-31
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	1-8036
CY2020	dei	Entity Registrant Name EntityRegistrantName	WEST PHARMACEUTICAL SERVICES, INC.
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	PA
CY2020	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2020	dei	Entity Shell Company EntityShellCompany	false
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	23-1210010
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	530 Herman O. West Drive
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Exton
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	PA
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	19341-0645
CY2020	dei	City Area Code CityAreaCode	610
CY2020	dei	Local Phone Number LocalPhoneNumber	594-2900
CY2020	dei	Security12b Title Security12bTitle	Common Stock, par value $.25 per share
CY2020	dei	Trading Symbol TradingSymbol	WST
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2020	dei	Entity Small Business EntitySmallBusiness	false
CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2020Q2	dei	Entity Public Float EntityPublicFloat	16742194934	USD
CY2021Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	74103026	shares
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2146900000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1839900000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1717400000	USD
CY2020	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1379100000	USD
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CY2018	us-gaap	Gross Profit GrossProfit	545400000	USD
CY2020	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	46900000	USD
CY2019	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	38900000	USD
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CY2020	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	302000000.0	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	272700000	USD
CY2018	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	262900000	USD
CY2020	wst	Other Income Expense OtherIncomeExpense	-12000000.0	USD
CY2019	wst	Other Income Expense OtherIncomeExpense	2500000	USD
CY2018	wst	Other Income Expense OtherIncomeExpense	-1900000	USD
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CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	296600000	USD
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CY2018	us-gaap	Interest Expense InterestExpense	8400000	USD
CY2020	us-gaap	Investment Income Net InvestmentIncomeNet	1400000	USD
CY2019	us-gaap	Investment Income Net InvestmentIncomeNet	3800000	USD
CY2018	us-gaap	Investment Income Net InvestmentIncomeNet	2100000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	1200000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-100000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	6700000	USD
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CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	72500000	USD
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CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	8900000	USD
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CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	200000	USD
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CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	-1100000	USD
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CY2019Q4	us-gaap	Inventory Net InventoryNet	235700000	USD
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CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-137100000	USD
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CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	439100000	USD
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CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	439100000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	337400000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	8100000	USD
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CY2018	us-gaap	Interest Paid Net InterestPaidNet	8400000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	48400000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	47500000	USD
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CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	31300000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	17000000.0	USD
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	15000000.0	USD
CY2020Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	12600000	USD
CY2019Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11800000	USD
CY2018Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11300000	USD
CY2020	us-gaap	Other Significant Noncash Transaction Value Of Consideration Given1 OtherSignificantNoncashTransactionValueOfConsiderationGiven1	0	USD
CY2019	us-gaap	Other Significant Noncash Transaction Value Of Consideration Given1 OtherSignificantNoncashTransactionValueOfConsiderationGiven1	4900000	USD
CY2018	us-gaap	Other Significant Noncash Transaction Value Of Consideration Given1 OtherSignificantNoncashTransactionValueOfConsiderationGiven1	0	USD
CY2019Q2	us-gaap	Business Acquisition Cost Of Acquired Entity Transaction Costs BusinessAcquisitionCostOfAcquiredEntityTransactionCosts	18900000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Inventory BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory	4500000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Property Plant And Equipment BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment	600000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired Goodwill And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet	2600000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangible Assets Other Than Goodwill BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill	11200000	USD
CY2020	us-gaap	Use Of Estimates UseOfEstimates	<span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Use of Estimates:</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> The financial statements are prepared in conformity with U.S. GAAP. These principles require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingencies in the financial statements. Actual amounts realized may differ from these estimates.</span>
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1100000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	500000	USD
CY2020Q4	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	132900000	USD
CY2019Q4	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	97400000	USD
CY2020Q4	us-gaap	Inventory Net InventoryNet	321300000	USD
CY2020Q4	us-gaap	Inventory Raw Materials Net Of Reserves InventoryRawMaterialsNetOfReserves	133500000	USD
CY2019Q4	us-gaap	Inventory Raw Materials Net Of Reserves InventoryRawMaterialsNetOfReserves	100900000	USD
CY2020Q4	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	54900000	USD
CY2019Q4	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	37400000	USD
CY2019Q4	us-gaap	Inventory Net InventoryNet	235700000	USD
CY2020	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2019	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2020	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2019	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2020	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2019	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2019Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	9800000	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	10900000	USD
CY2020	wst	Contract With Customer Asset Increase Decrease ContractWithCustomerAssetIncreaseDecrease	1100000	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	34900000	USD
CY2020Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	57100000	USD
CY2020	us-gaap	Contract With Customer Liability Change In Timeframe Performance Obligation Satisfied Revenue Recognized ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized	-22200000	USD
CY2020	wst	Contract With Customer Liability Increase Decrease Due To Additional Cash Payments ContractWithCustomerLiabilityIncreaseDecreaseDueToAdditionalCashPayments	100300000	USD
CY2020	wst	Contract With Customer Liability Revenue Recognized During The Period ContractWithCustomerLiabilityRevenueRecognizedDuringThePeriod	83900000	USD
CY2020Q1	wst	Contract With Customer Liability Revenue Recognized During The Period ContractWithCustomerLiabilityRevenueRecognizedDuringThePeriod	26900000	USD
CY2020Q4	us-gaap	Transfer Of Financial Assets Accounted For As Sales Cash Proceeds Received For Assets Derecognized Amount TransferOfFinancialAssetsAccountedForAsSalesCashProceedsReceivedForAssetsDerecognizedAmount	14100000	USD
CY2019Q4	us-gaap	Transfer Of Financial Assets Accounted For As Sales Cash Proceeds Received For Assets Derecognized Amount TransferOfFinancialAssetsAccountedForAsSalesCashProceedsReceivedForAssetsDerecognizedAmount	10100000	USD
CY2018Q4	wst	Provision For Product Returns ProvisionForProductReturns	11300000	USD
CY2019	wst	Provision For Product Returns ProvisionForProductReturns	5400000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	346200000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	241700000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	206900000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73900000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	74000000.0	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73900000	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1900000	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1400000	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1500000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	75800000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	75400000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	75400000	shares
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0.0	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	100000	shares
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	400000	shares
CY2019Q4	us-gaap	Stock Repurchase Program Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased	848000	shares
CY2020Q4	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	0	shares
CY2020	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	761500	shares
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	115500000	USD
CY2020	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	151.65
CY2020Q4	us-gaap	Stock Repurchase Program Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased	631000	shares
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	2035500000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1820100000	USD
CY2020	us-gaap	Depreciation Depreciation	104700000	USD
CY2019	us-gaap	Depreciation Depreciation	100000000.0	USD
CY2018	us-gaap	Depreciation Depreciation	101700000	USD
CY2020	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	1400000	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	1000000.0	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	900000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	300000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	2200000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	1900000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	1100000	USD
CY2020	wst	Lessee Operating Lease Option To Terminate Term LesseeOperatingLeaseOptionToTerminateTerm	P1Y
CY2020Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	0	USD
CY2019Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	0	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	12800000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	12900000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	800000	USD
CY2019	us-gaap	Short Term Lease Cost ShortTermLeaseCost	800000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	3800000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	3300000	USD
CY2020	us-gaap	Lease Cost LeaseCost	17400000	USD
CY2019	us-gaap	Lease Cost LeaseCost	17000000.0	USD
CY2018	us-gaap	Operating Leases Rent Expense Net OperatingLeasesRentExpenseNet	14500000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	12600000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	12500000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	6100000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	9100000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P11Y1M6D
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P11Y8M12D
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0368
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0376
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	12400000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	10400000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	9300000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	8700000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	6900000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	37500000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	85200000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	14700000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	70500000	USD
CY2019Q4	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	85100000	USD
CY2019Q4	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	4900000	USD
CY2019Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	20800000	USD
CY2020	wst	Sales To Equity Method Investees SalesToEquityMethodInvestees	9700000	USD
CY2019	wst	Sales To Equity Method Investees SalesToEquityMethodInvestees	9200000	USD
CY2018	wst	Sales To Equity Method Investees SalesToEquityMethodInvestees	9600000	USD
CY2020Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	12800000	USD
CY2020Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	98200000	USD
CY2019Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	82400000	USD
CY2018Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	75800000	USD
CY2020	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	1600000	USD
CY2019	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	2200000	USD
CY2018	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	1700000	USD
CY2020	wst	Purchases And Royalty Payments From Equity Method Investees PurchasesAndRoyaltyPaymentsFromEquityMethodInvestees	143300000	USD
CY2019	wst	Purchases And Royalty Payments From Equity Method Investees PurchasesAndRoyaltyPaymentsFromEquityMethodInvestees	115100000	USD
CY2018	wst	Purchases And Royalty Payments From Equity Method Investees PurchasesAndRoyaltyPaymentsFromEquityMethodInvestees	86300000	USD
CY2020Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	33600000	USD
CY2020Q4	us-gaap	Due From Affiliates DueFromAffiliates	1400000	USD
CY2019Q4	us-gaap	Due From Affiliates DueFromAffiliates	1900000	USD
CY2020Q4	us-gaap	Equity Method Investments EquityMethodInvestments	201900000	USD
CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	179300000	USD
CY2019Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13400000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	105800000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	2600000	USD
CY2019	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-600000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	107800000	USD
CY2020	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	3300000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	111100000	USD
CY2020Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	0	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	83200000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	52700000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	30500000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	78100000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	48300000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	29800000	USD
CY2020	us-gaap	Finite Lived Intangible Assets Foreign Currency Translation Gain Loss FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss	1300000	USD
CY2019	us-gaap	Finite Lived Intangible Assets Foreign Currency Translation Gain Loss FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss	-300000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4400000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3400000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2700000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	3800000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	3800000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	3700000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	3600000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	3400000	USD
CY2019Q4	us-gaap	Accrued Sales Commission Current And Noncurrent AccruedSalesCommissionCurrentAndNoncurrent	9700000	USD
CY2019Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11800000	USD
CY2020Q4	us-gaap	Accrued Sales Commission Current And Noncurrent AccruedSalesCommissionCurrentAndNoncurrent	10000000.0	USD
CY2020Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	51000000.0	USD
CY2019Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	27500000	USD
CY2020Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	12600000	USD
CY2020Q4	us-gaap	Other Postretirement Benefits Payable Current And Noncurrent OtherPostretirementBenefitsPayableCurrentAndNoncurrent	8400000	USD
CY2019Q4	us-gaap	Other Postretirement Benefits Payable Current And Noncurrent OtherPostretirementBenefitsPayableCurrentAndNoncurrent	7900000	USD
CY2020Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	15400000	USD
CY2019Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	6500000	USD
CY2020Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	3700000	USD
CY2019Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	5900000	USD
CY2020Q4	us-gaap	Interest Payable Current InterestPayableCurrent	3300000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	3300000	USD
CY2020Q4	us-gaap	Restructuring Reserve RestructuringReserve	7800000	USD
CY2019Q4	us-gaap	Restructuring Reserve RestructuringReserve	2600000	USD
CY2020Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	9500000	USD
CY2019Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	200000	USD
CY2020Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	21900000	USD
CY2019Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	15900000	USD
CY2020Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	143600000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	91300000	USD
CY2020Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	255700000	USD
CY2019Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	258000000.0	USD
CY2020Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	500000	USD
CY2019Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	700000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	255200000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	257300000	USD
CY2020Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	2300000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	2300000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	252900000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	255000000.0	USD
CY2012Q4	wst	Debt Instrument Number Of Tranches DebtInstrumentNumberOfTranches	3	tranche
CY2020	us-gaap	Interest Expense Debt InterestExpenseDebt	9600000	USD
CY2019	us-gaap	Interest Expense Debt InterestExpenseDebt	9400000	USD
CY2018	us-gaap	Interest Expense Debt InterestExpenseDebt	9300000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	2300000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	44200000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	2200000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	134000000.0	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	0.0	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	73000000.0	USD
CY2020	us-gaap	Gain Loss On Fair Value Hedges Recognized In Earnings GainLossOnFairValueHedgesRecognizedInEarnings	6100000	USD
CY2019	us-gaap	Gain Loss On Fair Value Hedges Recognized In Earnings GainLossOnFairValueHedgesRecognizedInEarnings	6900000	USD
CY2020Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	12800000	USD
CY2020Q4	us-gaap	Foreign Currency Contract Asset Fair Value Disclosure ForeignCurrencyContractAssetFairValueDisclosure	3000000.0	USD
CY2020Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	16100000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-2100000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	500000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	1700000	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3300000	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-1200000	USD
CY2020Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	3600000	USD
CY2020Q4	us-gaap	Other Deferred Compensation Arrangements Liability Classified Noncurrent OtherDeferredCompensationArrangementsLiabilityClassifiedNoncurrent	14500000	USD
CY2020Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	33400000	USD
CY2019Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	11300000	USD
CY2019Q4	us-gaap	Foreign Currency Contract Asset Fair Value Disclosure ForeignCurrencyContractAssetFairValueDisclosure	7700000	USD
CY2019Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	19100000	USD
CY2019Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	3300000	USD
CY2019Q4	us-gaap	Other Deferred Compensation Arrangements Liability Classified Noncurrent OtherDeferredCompensationArrangementsLiabilityClassifiedNoncurrent	12800000	USD
CY2019Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	17800000	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	900000	USD
CY2020Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3600000	USD
CY2020Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	265700000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	252900000	USD
CY2019Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	263300000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	255000000.0	USD
CY2019	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	8400000	USD
CY2019	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	3800000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	4600000	USD
CY2020	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	40600000	USD
CY2020	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	1600000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	39000000.0	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	2761911	shares
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	34000000.0	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	24400000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	15100000	USD
CY2020Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	31700000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y7M6D
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2700000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	3000000.0	shares
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	3500000	shares
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	200000	shares
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	300000	shares
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	500000	shares
CY2020	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	500000	shares
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	600000	shares
CY2018	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1000000.0	shares
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2400000	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2700000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	3000000.0	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	1600000	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	1600000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	1700000	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	67.02
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	58.93
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	48.76
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	178.11
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	103.40
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	90.36
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	49.99
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	46.42
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CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	103.51
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	92.71
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	75.32
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	81.37
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	67.02
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	58.93
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	62.42
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	53.12
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	45.32
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P5Y10M24D
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y9M18D
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	481200000	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue	351700000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	40.28
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	24.72
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	20.16
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	88800000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	46900000	USD
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	61300000	USD
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	8400000	USD
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	7500000	USD
CY2018	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	8300000	USD
CY2020Q4	wst	Cash Settled Stock Appreciation Rights Outstanding CashSettledStockAppreciationRightsOutstanding	24051	shares
CY2020Q4	wst	Stock Settled Stock Appreciation Rights Outstanding StockSettledStockAppreciationRightsOutstanding	3628	shares
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	16800000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	15600000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	6500000	USD
CY2020	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	0	USD
CY2019	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	2600000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	293900000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	283900000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	24300000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	17800000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	16900000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	17200000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	17100000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	74700000	USD
CY2020Q4	wst	Defined Benefit Plan Expected Future Benefit Payments DefinedBenefitPlanExpectedFutureBenefitPayments	168000000.0	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Employer Contributions Next Fiscal Year DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear	3600000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Health Care Cost Trend Rate Assumed Next Fiscal Year DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear	0.0650
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CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	258100000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	244100000	USD
CY2020	us-gaap	Severance Costs1 SeveranceCosts1	4600000	USD
CY2019	us-gaap	Severance Costs1 SeveranceCosts1	2600000	USD
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CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	300000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	2200000	USD
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CY2019	us-gaap	Other Restructuring Costs OtherRestructuringCosts	2000000.0	USD
CY2018	us-gaap	Other Restructuring Costs OtherRestructuringCosts	3800000	USD
CY2020	us-gaap	Restructuring And Related Cost Incurred Cost RestructuringAndRelatedCostIncurredCost	4600000	USD
CY2019	us-gaap	Restructuring And Related Cost Incurred Cost RestructuringAndRelatedCostIncurredCost	4900000	USD
CY2018	us-gaap	Restructuring And Related Cost Incurred Cost RestructuringAndRelatedCostIncurredCost	9100000	USD
CY2020	us-gaap	Other Asset Impairment Charges OtherAssetImpairmentCharges	7700000	USD
CY2019	us-gaap	Other Asset Impairment Charges OtherAssetImpairmentCharges	800000	USD
CY2018	us-gaap	Other Asset Impairment Charges OtherAssetImpairmentCharges	1800000	USD
CY2020	us-gaap	Foreign Currency Transaction Loss Before Tax ForeignCurrencyTransactionLossBeforeTax	0	USD
CY2019	us-gaap	Foreign Currency Transaction Loss Before Tax ForeignCurrencyTransactionLossBeforeTax	1000000.0	USD
CY2018	us-gaap	Foreign Currency Transaction Loss Before Tax ForeignCurrencyTransactionLossBeforeTax	1100000	USD
CY2020	wst	Brazil Tax Recovery BrazilTaxRecovery	0	USD
CY2019	wst	Brazil Tax Recovery BrazilTaxRecovery	4700000	USD
CY2018	wst	Brazil Tax Recovery BrazilTaxRecovery	0	USD
CY2020	wst	Development And Licensing Income DevelopmentAndLicensingIncome	900000	USD
CY2019	wst	Development And Licensing Income DevelopmentAndLicensingIncome	900000	USD
CY2018	wst	Development And Licensing Income DevelopmentAndLicensingIncome	900000	USD
CY2020	us-gaap	Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1	1200000	USD
CY2019	us-gaap	Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1	2100000	USD
CY2018	us-gaap	Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1	-2600000	USD
CY2020	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	1500000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	4600000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	5500000	USD
CY2020	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	-900000	USD
CY2019	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	1100000	USD
CY2018	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	1100000	USD
CY2020	wst	Other Income Expense OtherIncomeExpense	-12000000.0	USD
CY2019	wst	Other Income Expense OtherIncomeExpense	2500000	USD
CY2018	wst	Other Income Expense OtherIncomeExpense	-1900000	USD
CY2019	wst	Brazil Tax Recovery BrazilTaxRecovery	4700000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	5000000.0	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3900000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	4900000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1600000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	130600000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	600000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	100000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	500000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	10400000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	5000000.0	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	300000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	200000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	10400000	USD
CY2020Q4	us-gaap	Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit	-300000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	227000000.0	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	161200000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	132900000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	174300000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	107800000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	401300000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	291800000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	240700000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	28900000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	10800000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	2100000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	3400000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	2400000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	3300000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	46000000.0	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	30500000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	35100000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	78300000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	43700000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	40500000	USD
CY2020	wst	Deferred Federal State And Local Income Tax Expense Benefit DeferredFederalStateAndLocalIncomeTaxExpenseBenefit	200000	USD
CY2019	wst	Deferred Federal State And Local Income Tax Expense Benefit DeferredFederalStateAndLocalIncomeTaxExpenseBenefit	10300000	USD
CY2018	wst	Deferred Federal State And Local Income Tax Expense Benefit DeferredFederalStateAndLocalIncomeTaxExpenseBenefit	1400000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-6000000.0	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	5000000.0	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-500000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5800000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	15300000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	900000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	72500000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	59000000.0	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	41400000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	21400000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	21900000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	2000000.0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	2800000	USD
CY2020Q4	wst	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Restructuring And Impairment Charges DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsRestructuringAndImpairmentCharges	400000	USD
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CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	35300000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	25600000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	10600000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	9200000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	15100000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	15900000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	54600000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	43600000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	42100000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	37900000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	6500000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	6300000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	400000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	900000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	49000000.0	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	45100000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	5600000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	1500000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.012
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.027
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.048
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.014
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.004
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.002
CY2020	wst	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings Net Of Foreign Tax Credits Percent EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarningsNetOfForeignTaxCreditsPercent	0.004
CY2019	wst	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings Net Of Foreign Tax Credits Percent EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarningsNetOfForeignTaxCreditsPercent	0.004
CY2018	wst	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings Net Of Foreign Tax Credits Percent EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarningsNetOfForeignTaxCreditsPercent	-0.002
CY2020	wst	Effective Income Tax Rate Reconciliation Foreign Derived Intangible Income Deductions Fdii Percent EffectiveIncomeTaxRateReconciliationForeignDerivedIntangibleIncomeDeductionsFDIIPercent	-0.011
CY2019	wst	Effective Income Tax Rate Reconciliation Foreign Derived Intangible Income Deductions Fdii Percent EffectiveIncomeTaxRateReconciliationForeignDerivedIntangibleIncomeDeductionsFDIIPercent	-0.006
CY2018	wst	Effective Income Tax Rate Reconciliation Foreign Derived Intangible Income Deductions Fdii Percent EffectiveIncomeTaxRateReconciliationForeignDerivedIntangibleIncomeDeductionsFDIIPercent	-0.004
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.012
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.014
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.023
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.007
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.010
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.009
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	-0.052
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	-0.035
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	-0.060
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	-0.029
CY2020	wst	Effective Income Tax Rate Reconciliation Undistributed Earnings Of Subsidiaries Percentage EffectiveIncomeTaxRateReconciliationUndistributedEarningsOfSubsidiariesPercentage	0.001
CY2019	wst	Effective Income Tax Rate Reconciliation Undistributed Earnings Of Subsidiaries Percentage EffectiveIncomeTaxRateReconciliationUndistributedEarningsOfSubsidiariesPercentage	-0.002
CY2018	wst	Effective Income Tax Rate Reconciliation Undistributed Earnings Of Subsidiaries Percentage EffectiveIncomeTaxRateReconciliationUndistributedEarningsOfSubsidiariesPercentage	-0.013
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.002
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.004
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.006
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.181
CY2017	us-gaap	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Income Tax Expense TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpense	27900000	USD
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.202
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.172
CY2020	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	-500000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-20800000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	-300000	USD
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-10300000	USD
CY2018	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	-2500000	USD
CY2018	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-14300000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Income Tax Expense TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpense	-7500000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Measurement Period Adjustment Income Tax Expense Benefit TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit	4000000.0	USD
	us-gaap	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Income Tax Expense TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpense	20400000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Measurement Period Adjustment Increase Decrease In Effective Tax Rate TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncreaseDecreaseInEffectiveTaxRate	0.0145
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	14000000.0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Foreign DeferredTaxAssetsOperatingLossCarryforwardsForeign	7400000	USD
CY2020Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	345600000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance Sheet Amount UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount	118400000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On First Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary	41400000	USD
CY2020	wst	Contingent Consideration Arrangements Range Of Outcomes Payable Period ContingentConsiderationArrangementsRangeOfOutcomesPayablePeriod	P5Y
CY2020Q4	us-gaap	Business Combination Contingent Consideration Arrangements Range Of Outcomes Value Low BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow	0	USD
CY2020Q4	us-gaap	Business Combination Contingent Consideration Arrangements Range Of Outcomes Value High BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh	4300000	USD
CY2020	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2020	us-gaap	Revenues Revenues	2146900000	USD
CY2019	us-gaap	Revenues Revenues	1839900000	USD
CY2018	us-gaap	Revenues Revenues	1717400000	USD
CY2020	us-gaap	Revenues Revenues	2146900000	USD
CY2019	us-gaap	Revenues Revenues	1839900000	USD
CY2018	us-gaap	Revenues Revenues	1717400000	USD
CY2020Q4	us-gaap	Noncurrent Assets NoncurrentAssets	1011500000	USD
CY2019Q4	us-gaap	Noncurrent Assets NoncurrentAssets	909400000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	406900000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	296600000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	240300000	USD
CY2020	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-5600000	USD
CY2019	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-4800000	USD
CY2018	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	400000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	401300000	USD
CY2020Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	548000000.0	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	291800000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	240700000	USD
CY2020Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	600000	USD
CY2020Q4	us-gaap	Assets Assets	2793800000	USD
CY2019Q4	us-gaap	Assets Assets	2341400000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	109100000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	103400000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	104400000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	174400000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	126400000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	104700000	USD
CY2020Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	491500000	USD
CY2020Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	527200000	USD
CY2020Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	548000000.0	USD
CY2020Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	580200000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	82300000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2146900000	USD
CY2020Q1	us-gaap	Gross Profit GrossProfit	167000000.0	USD
CY2020Q2	us-gaap	Gross Profit GrossProfit	195100000	USD
CY2020Q3	us-gaap	Gross Profit GrossProfit	194600000	USD
CY2020Q3	us-gaap	Gross Profit GrossProfit	194600000	USD
CY2020Q4	us-gaap	Gross Profit GrossProfit	211100000	USD
CY2020	us-gaap	Gross Profit GrossProfit	767800000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	74300000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	91200000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	82300000	USD
CY2020Q4	us-gaap	Net Income Loss NetIncomeLoss	98400000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	346200000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.01
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.24
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.11
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.32
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.68
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.99
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.21
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.09
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.29
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.57
CY2019Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	443500000	USD
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	469700000	USD
CY2019Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	456100000	USD
CY2019Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	470600000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1839900000	USD
CY2019Q1	us-gaap	Gross Profit GrossProfit	146800000	USD
CY2019Q2	us-gaap	Gross Profit GrossProfit	157900000	USD
CY2019Q3	us-gaap	Gross Profit GrossProfit	147800000	USD
CY2020Q1	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.07
CY2019Q1	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	400000	USD
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.21
CY2020Q1	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	1100000	USD
CY2020Q1	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2020Q1	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	5100000	USD
CY2019Q1	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2019Q1	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	1400000	USD
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.90
CY2019Q4	us-gaap	Gross Profit GrossProfit	153200000	USD
CY2019	us-gaap	Gross Profit GrossProfit	605700000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	55400000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	66100000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	56300000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	63900000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	241700000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.75
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.76
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.86
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.27
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.73
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.88
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.75
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.84
CY2019Q1	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.02
CY2019Q2	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	1100000	USD
CY2019Q2	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2020Q2	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	700000	USD
CY2020Q2	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2020Q2	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	1600000	USD
CY2020Q2	wst	Payments To Acquire Intangible Assets Impact On Diluted Earnings Per Share PaymentsToAcquireIntangibleAssetsImpactOnDilutedEarningsPerShare	0.02
CY2020Q2	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	6900000	USD
CY2020Q2	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.09
CY2019Q2	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	3800000	USD
CY2019Q2	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.05
CY2020Q3	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	800000	USD
CY2020Q3	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2020Q3	wst	Restructuring And Severance Related Charges RestructuringAndSeveranceRelatedCharges	3400000	USD
CY2020Q3	wst	Restructuring And Severance Related Charges Impact On Diluted Earnings Per Share RestructuringAndSeveranceRelatedChargesImpactOnDilutedEarningsPerShare	0.04
CY2020Q3	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	2000000.0	USD
CY2020Q3	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.02
CY2019Q3	wst	Restructuring And Severance Related Charges RestructuringAndSeveranceRelatedCharges	1400000	USD
CY2019Q3	wst	Restructuring And Severance Related Charges Impact On Diluted Earnings Per Share RestructuringAndSeveranceRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2019Q4	wst	Restructuring And Severance Related Charges RestructuringAndSeveranceRelatedCharges	800000	USD
CY2019Q3	wst	Foreign Currency Charges From Devaluation Of Argentina Currency Impact On Diluted Earnings Per Share ForeignCurrencyChargesFromDevaluationOfArgentinaCurrencyImpactOnDilutedEarningsPerShare	0.01
CY2019Q3	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	1000000.0	USD
CY2019Q3	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	2100000	USD
CY2019Q3	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.03
CY2019Q3	wst	Foreign Currency Charges From Devaluation Of Argentina Currency ForeignCurrencyChargesFromDevaluationOfArgentinaCurrency	700000	USD
CY2019Q3	wst	Income Tax Benefit From Change In Enacted Tax Rate Impact On Diluted Earnings Per Share IncomeTaxBenefitFromChangeInEnactedTaxRateImpactOnDilutedEarningsPerShare	0.01
CY2019Q3	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	4000000.0	USD
CY2019Q3	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.05
CY2020Q4	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	300000	USD
CY2020Q4	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2020Q4	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	2500000	USD
CY2020Q4	wst	Payments To Acquire Intangible Assets Impact On Diluted Earnings Per Share PaymentsToAcquireIntangibleAssetsImpactOnDilutedEarningsPerShare	0.03
CY2020Q4	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	6800000	USD
CY2020Q4	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.09
CY2019Q4	wst	Restructuring And Severance Related Charges Impact On Diluted Earnings Per Share RestructuringAndSeveranceRelatedChargesImpactOnDilutedEarningsPerShare	0.02
CY2019Q4	wst	Fixed Asset Impairment From Restructuring FixedAssetImpairmentFromRestructuring	1300000	USD
CY2019Q4	wst	Fixed Asset Impairment From Restructuring Impact On Diluted Earnings Per Share FixedAssetImpairmentFromRestructuringImpactOnDilutedEarningsPerShare	0.02
CY2019Q4	wst	Pension Settlement And Related Charges Impact On Diluted Earnings Per Share PensionSettlementAndRelatedChargesImpactOnDilutedEarningsPerShare	0.01
CY2019Q4	wst	Payment Of Excise Taxes PaymentOfExciseTaxes	2900000	USD
CY2019Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	16400000	USD
CY2019Q4	wst	Pension Settlement And Related Charges PensionSettlementAndRelatedCharges	600000	USD
CY2019Q4	wst	Payment Of Excise Taxes Impact On Diluted Earnings Share PaymentOfExciseTaxesImpactOnDilutedEarningsShare	0.04
CY2019Q4	wst	Foreign Currency Charges From Devaluation Of Argentina Currency ForeignCurrencyChargesFromDevaluationOfArgentinaCurrency	700000	USD
CY2019Q4	wst	Foreign Currency Charges From Devaluation Of Argentina Currency Impact On Diluted Earnings Per Share ForeignCurrencyChargesFromDevaluationOfArgentinaCurrencyImpactOnDilutedEarningsPerShare	0.01
CY2019Q4	wst	Income Tax Benefit From Stock Based Compensation IncomeTaxBenefitFromStockBasedCompensation	1100000	USD
CY2019Q4	wst	Income Tax Benefit From Stock Based Compensation Impact On Diluted Earnings Per Share IncomeTaxBenefitFromStockBasedCompensationImpactOnDilutedEarningsPerShare	0.02
CY2020	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	700000	USD
CY2020	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	900000	USD
CY2020Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	16200000	USD
CY2018Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	18000000.0	USD
CY2019	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	100000	USD
CY2019	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	1700000	USD
CY2019Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	16400000	USD
CY2017Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	21400000	USD
CY2018	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	-2300000	USD
CY2018	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	1100000	USD
CY2018Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	18000000.0	USD

Files In Submission

Name	View Source	Status
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0000105770-21-000008-index.html	Edgar Link	pending
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$WST
WEST PHARMACEUTICAL SERVICES INC Stock $wst

2020 Q4 Form 10-K Financial Statement

#000010577021000008 Filed on February 23, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WST WEST PHARMACEUTICAL SERVICES INC Stock $wst

2020 Q4 Form 10-K Financial Statement

#000010577021000008 Filed on February 23, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WST
WEST PHARMACEUTICAL SERVICES INC Stock $wst