$WST
WEST PHARMACEUTICAL SERVICES INC Stock $wst

$wst Overview Financials Valuation SEC Filings Company Website

2019 Form 10-K Financial Statement

#000010577020000015 Filed on February 24, 2020

Income Statement

Concept	2019	2018 Q4	2018
Revenue	$1.840B	$422.5M	$1.717B
YoY Change	7.13%	1.66%	7.4%
Cost Of Revenue	$1.234B	$289.3M	$1.172B
YoY Change	5.31%	0.77%	7.9%
Gross Profit	$605.7M	$133.2M	$545.4M
YoY Change	11.06%	3.66%	6.34%
Gross Profit Margin	32.92%	31.53%	31.76%
Selling, General & Admin	$272.7M	$59.70M	$262.9M
YoY Change	3.73%	1.36%	6.87%
% of Gross Profit	45.02%	44.82%	48.2%
Research & Development	$38.90M	$9.800M	$40.30M
YoY Change	-3.47%	1.03%	3.07%
% of Gross Profit	6.42%	7.36%	7.39%
Depreciation & Amortization	$103.4M	$26.30M	$104.4M
YoY Change	-0.96%	5.62%	7.96%
% of Gross Profit	17.07%	19.74%	19.14%
Operating Expenses	$311.6M	$65.00M	$303.2M
YoY Change	2.77%	-3.7%	6.35%
Operating Profit	$296.6M	$68.20M	$240.3M
YoY Change	23.43%	11.8%	6.42%
Interest Expense	$8.500M	-$1.600M	$8.400M
YoY Change	1.19%	-5.88%	7.69%
% of Operating Profit	2.87%	-2.35%	3.5%
Other Income/Expense, Net	-$4.800M	$1.600M	$400.0K
YoY Change	-1300.0%		-87.1%
Pretax Income	$161.2M	$65.80M	$132.9M
YoY Change	21.29%	10.96%	37.72%
Income Tax	$59.00M	$17.70M	$41.40M
% Of Pretax Income	36.6%	26.9%	31.15%
Net Earnings	$241.7M	$52.00M	$206.9M
YoY Change	16.82%		37.29%
Net Earnings / Revenue	13.14%	12.31%	12.05%
Basic Earnings Per Share	$3.27		$2.80
Diluted Earnings Per Share	$3.21	$0.69	$2.74
COMMON SHARES
Basic Shares Outstanding	74.00M shares		73.90M shares
Diluted Shares Outstanding	75.40M shares		75.40M shares

Balance Sheet

Concept	2019	2018 Q4	2018
SHORT-TERM ASSETS
Cash & Short-Term Investments	$439.1M	$337.4M	$337.4M
YoY Change	30.14%	43.03%	43.03%
Cash & Equivalents	$439.1M	$337.4M	$337.4M
Short-Term Investments
Other Short-Term Assets	$64.60M	$54.30M	$54.30M
YoY Change	18.97%	38.52%	38.52%
Inventory	$235.7M	$214.5M	$214.5M
Prepaid Expenses
Receivables	$319.3M	$288.2M	$288.2M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$1.059B	$894.4M	$894.4M
YoY Change	18.37%	20.3%	20.3%
LONG-TERM ASSETS
Property, Plant & Equipment	$909.4M	$822.0M	$822.0M
YoY Change	10.63%	-3.86%	-3.86%
Goodwill		$105.8M
YoY Change		-1.76%
Intangibles		$20.30M
YoY Change		-6.45%
Long-Term Investments	$192.7M	$77.80M	$91.20M
YoY Change	111.29%	7.46%	6.29%
Other Assets	$43.00M	$20.50M	$45.20M
YoY Change	-4.87%	-12.39%	-7.94%
Total Long-Term Assets	$1.283B	$1.085B	$1.085B
YoY Change	18.28%	-3.11%	-3.11%
TOTAL ASSETS
Total Short-Term Assets	$1.059B	$894.4M	$894.4M
Total Long-Term Assets	$1.283B	$1.085B	$1.085B
Total Assets	$2.341B	$1.979B	$1.979B
YoY Change	18.32%	6.23%	6.23%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$156.8M	$130.4M	$130.4M
YoY Change	20.25%	-5.58%	-5.58%
Accrued Expenses	$135.3M	$66.80M	$93.00M
YoY Change	45.48%	14.38%	8.01%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$2.300M	$100.0K	$100.0K
YoY Change	2200.0%
Total Short-Term Liabilities	$341.6M	$283.7M	$283.7M
YoY Change	20.41%	1.5%	1.5%
LONG-TERM LIABILITIES
Long-Term Debt	$255.0M	$196.0M	$196.0M
YoY Change	30.1%	-0.51%	-0.51%
Other Long-Term Liabilities	$156.1M	$33.60M	$89.80M
YoY Change	73.83%	-21.13%	-6.46%
Total Long-Term Liabilities	$411.1M	$229.6M	$285.8M
YoY Change	43.84%	-4.17%	-2.46%
TOTAL LIABILITIES
Total Short-Term Liabilities	$341.6M	$283.7M	$283.7M
Total Long-Term Liabilities	$411.1M	$229.6M	$285.8M
Total Liabilities	$768.2M	$582.6M	$582.6M
YoY Change	31.86%	-0.05%	-0.05%
SHAREHOLDERS EQUITY
Retained Earnings		$1.353B
YoY Change		14.87%
Common Stock		$18.80M
YoY Change		0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)		$103.7M
YoY Change		-4.95%
Treasury Stock Shares		1.200M shares
Shareholders Equity	$1.573B	$1.396B	$1.396B
YoY Change
Total Liabilities & Shareholders Equity	$2.341B	$1.979B	$1.979B
YoY Change	18.32%	6.23%	6.23%

Cashflow Statement

Concept	2019	2018 Q4	2018
OPERATING ACTIVITIES
Net Income	$241.7M	$52.00M	$206.9M
YoY Change	16.82%		37.29%
Depreciation, Depletion And Amortization	$103.4M	$26.30M	$104.4M
YoY Change	-0.96%	5.62%	7.96%
Cash From Operating Activities	$367.2M	$73.20M	$288.6M
YoY Change	27.23%	-10.18%	9.61%
INVESTING ACTIVITIES
Capital Expenditures	$126.4M	$30.00M	$104.7M
YoY Change	20.73%	1.69%	-19.95%
Acquisitions
YoY Change
Other Investing Activities	-$2.400M	$1.400M	-$3.900M
YoY Change	-38.46%	1300.0%	21.88%
Cash From Investing Activities	-$228.0M	-$28.60M	-$100.8M
YoY Change	126.19%	-2.72%	-24.55%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net	$83.10M		$70.80M
YoY Change	17.37%		-4.84%
Debt Paid & Issued, Net	$1.200M		$0.00
YoY Change			-100.0%
Cash From Financing Activities	-$36.80M	-8.200M	-$80.70M
YoY Change	-54.4%	-90.52%	-25.96%
NET CHANGE
Cash From Operating Activities	$367.2M	73.20M	$288.6M
Cash From Investing Activities	-$228.0M	-28.60M	-$100.8M
Cash From Financing Activities	-$36.80M	-8.200M	-$80.70M
Net Change In Cash	$101.7M	36.40M	$101.5M
YoY Change	0.2%	-205.81%	208.51%
FREE CASH FLOW
Cash From Operating Activities	$367.2M	$73.20M	$288.6M
Capital Expenditures	$126.4M	$30.00M	$104.7M
Free Cash Flow	$240.8M	$43.20M	$183.9M
YoY Change	30.94%	-16.92%	38.79%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2019	dei	Entity Registrant Name EntityRegistrantName	WEST PHARMACEUTICAL SERVICES, INC.
CY2019	dei	Entity Central Index Key EntityCentralIndexKey	0000105770
CY2019	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2019	dei	Document Period End Date DocumentPeriodEndDate	2019-12-31
CY2019	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
CY2019	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2019	dei	Amendment Flag AmendmentFlag	false
CY2020Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	73837449	shares
CY2019Q2	dei	Entity Public Float EntityPublicFloat	9218126218	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Benefit Plan Improvement Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBenefitPlanImprovementTaxEffect	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Benefit Plan Improvement Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBenefitPlanImprovementTaxEffect	0	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Benefit Plan Improvement Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBenefitPlanImprovementTaxEffect	0	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-300000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-200000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	1300000	USD
CY2019	wst	Other Comprehensive Income Loss Defined Benefit Plans Settlement Effects Arising During Period Tax OtherComprehensiveIncomeLossDefinedBenefitPlansSettlementEffectsArisingDuringPeriodTax	800000	USD
CY2018	wst	Other Comprehensive Income Loss Defined Benefit Plans Settlement Effects Arising During Period Tax OtherComprehensiveIncomeLossDefinedBenefitPlansSettlementEffectsArisingDuringPeriodTax	0	USD
CY2017	wst	Other Comprehensive Income Loss Defined Benefit Plans Settlement Effects Arising During Period Tax OtherComprehensiveIncomeLossDefinedBenefitPlansSettlementEffectsArisingDuringPeriodTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-300000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-500000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-100000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-500000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-500000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	-100000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	-2500000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax	-200000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax	1500000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax	-100000	USD
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	3000000.0	shares
CY2018Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	3000000.0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2018Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2018Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.25
CY2018Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.25
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	74100000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000.0	shares
CY2018Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000.0	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	75300000	shares
CY2018Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	75300000	shares
CY2018Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	74100000	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	1200000	shares
CY2018Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	1200000	shares
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.62
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.58
CY2017	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.54
CY2018Q4	us-gaap	Capital Leased Assets Gross CapitalLeasedAssetsGross	0	USD
CY2018Q4	us-gaap	Cost Method Investments CostMethodInvestments	13400000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	2300000	USD
CY2018	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	0	USD
CY2019	wst	Contingent Consideration Arrangements Rangeof Outcomes Payable Period ContingentConsiderationArrangementsRangeofOutcomesPayablePeriod	P5Y
CY2019	dei	Document Type DocumentType	10-K
CY2019	dei	Document Annual Report DocumentAnnualReport	true
CY2019	dei	Document Transition Report DocumentTransitionReport	false
CY2019	dei	Document Period End Date DocumentPeriodEndDate	2019-12-31
CY2019	dei	Entity File Number EntityFileNumber	1-8036
CY2019	dei	Entity Registrant Name EntityRegistrantName	WEST PHARMACEUTICAL SERVICES, INC.
CY2019	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	PA
CY2019	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	23-1210010
CY2019	dei	Entity Address Address Line1 EntityAddressAddressLine1	530 Herman O. West Drive
CY2019	dei	Entity Address City Or Town EntityAddressCityOrTown	Exton
CY2019	dei	Entity Address State Or Province EntityAddressStateOrProvince	PA
CY2019	dei	Trading Symbol TradingSymbol	WST
CY2019	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2019	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	19341-0645
CY2019	dei	City Area Code CityAreaCode	610
CY2019	dei	Local Phone Number LocalPhoneNumber	594-2900
CY2019	dei	Security12b Title Security12bTitle	Common Stock, par value $.25 per share
CY2019	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2019	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2019	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2019	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2019	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2019	dei	Entity Small Business EntitySmallBusiness	false
CY2019	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2019	dei	Entity Shell Company EntityShellCompany	false
CY2019Q2	dei	Entity Public Float EntityPublicFloat	9218126218	USD
CY2020Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	73837449	shares
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.74
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.74
CY2019	us-gaap	Revenues Revenues	1839900000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1234200000	USD
CY2018	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1172000000.0	USD
CY2017	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1086200000	USD
CY2019	us-gaap	Gross Profit GrossProfit	605700000	USD
CY2018	us-gaap	Gross Profit GrossProfit	545400000	USD
CY2017	us-gaap	Gross Profit GrossProfit	512900000	USD
CY2019	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	38900000	USD
CY2018	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	40300000	USD
CY2017	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	39100000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	272700000	USD
CY2018	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	262900000	USD
CY2017	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	246000000.0	USD
CY2019	wst	Other Income Expense OtherIncomeExpense	2500000	USD
CY2018	wst	Other Income Expense OtherIncomeExpense	-1900000	USD
CY2017	wst	Other Income Expense OtherIncomeExpense	-2000000.0	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	296600000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	240300000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	225800000	USD
CY2019	us-gaap	Interest Expense InterestExpense	8500000	USD
CY2018	us-gaap	Interest Expense InterestExpense	8400000	USD
CY2017	us-gaap	Interest Expense InterestExpense	7800000	USD
CY2019	us-gaap	Investment Income Net InvestmentIncomeNet	3800000	USD
CY2018	us-gaap	Investment Income Net InvestmentIncomeNet	2100000	USD
CY2017	us-gaap	Investment Income Net InvestmentIncomeNet	1300000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-100000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	6700000	USD
CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	3100000	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
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	222400000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	59000000.0	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	41400000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	80900000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	8900000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	7600000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	9200000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	241700000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	150700000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	206900000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	150700000	USD
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.27
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.80
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.04
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.21
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.74
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.99
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
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73900000	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
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	75800000	shares
CY2019	us-gaap	Profit Loss ProfitLoss	241700000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	206900000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	4900000	USD
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CY2017	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	68800000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	300000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-1900000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-700000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	6300000	USD
CY2019	wst	Other Comprehensive Loss Defined Benefit Plans Settlement Effects Netof Tax OtherComprehensiveLossDefinedBenefitPlansSettlementEffectsNetofTax	-2700000	USD
CY2018	wst	Other Comprehensive Loss Defined Benefit Plans Settlement Effects Netof Tax OtherComprehensiveLossDefinedBenefitPlansSettlementEffectsNetofTax	0	USD
CY2017	wst	Other Comprehensive Loss Defined Benefit Plans Settlement Effects Netof Tax OtherComprehensiveLossDefinedBenefitPlansSettlementEffectsNetofTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	200000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-1100000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-3600000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	-500000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	-1500000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	-3500000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-100000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-4700000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	-400000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	3800000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	-1000000.0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4600000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-36900000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	69500000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	246300000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	170000000.0	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	220200000	USD
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
CY2019Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	319300000	USD
CY2018Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	288200000	USD
CY2019Q4	us-gaap	Inventory Net InventoryNet	235700000	USD
CY2018Q4	us-gaap	Inventory Net InventoryNet	214500000	USD
CY2019Q4	us-gaap	Other Assets Current OtherAssetsCurrent	64600000	USD
CY2018Q4	us-gaap	Other Assets Current OtherAssetsCurrent	54300000	USD
CY2019Q4	us-gaap	Assets Current AssetsCurrent	1058700000	USD
CY2018Q4	us-gaap	Assets Current AssetsCurrent	894400000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1820100000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1752700000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	980800000	USD
CY2018Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	930700000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	839300000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	822000000.0	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	70100000	USD
CY2018Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	0	USD
CY2019Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	192700000	USD
CY2018Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	91200000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	107800000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	105800000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net Noncurrent DeferredTaxAssetsNetNoncurrent	14000000.0	USD
CY2018Q4	us-gaap	Deferred Tax Assets Net Noncurrent DeferredTaxAssetsNetNoncurrent	24700000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	29800000	USD
CY2018Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	20300000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Assets For Plan Benefits Noncurrent DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent	4300000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Assets For Plan Benefits Noncurrent DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent	0	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	24700000	USD
CY2018Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	20500000	USD
CY2019Q4	us-gaap	Assets Assets	2341400000	USD
CY2018Q4	us-gaap	Assets Assets	1978900000	USD
CY2019Q4	wst	Notes Payable And Other Debt Current NotesPayableAndOtherDebtCurrent	2300000	USD
CY2018Q4	wst	Notes Payable And Other Debt Current NotesPayableAndOtherDebtCurrent	100000	USD
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CY2018Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	130400000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	2200000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	2300000	USD
CY2019Q4	wst	Accrued Salaries Wages And Benefits Current AccruedSalariesWagesAndBenefitsCurrent	73000000.0	USD
CY2018Q4	wst	Accrued Salaries Wages And Benefits Current AccruedSalariesWagesAndBenefitsCurrent	64500000	USD
CY2019Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	6400000	USD
CY2018Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	9800000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	9600000	USD
CY2018Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	0	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	91300000	USD
CY2018Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	76600000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	341600000	USD
CY2018Q4	us-gaap	Liabilities Current LiabilitiesCurrent	283700000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	255000000.0	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	196000000.0	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	15500000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	13100000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	52500000	USD
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CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	62400000	USD
CY2018Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	0	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	41200000	USD
CY2018Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	33600000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	768200000	USD
CY2018Q4	us-gaap	Liabilities Liabilities	582600000	USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2018Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2018Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	18800000	USD
CY2018Q4	us-gaap	Common Stock Value CommonStockValue	18800000	USD
CY2019Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	272700000	USD
CY2018Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	282000000.0	USD
CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	118100000	USD
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CY2018Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1353400000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-149600000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-154200000	USD
CY2018Q4	us-gaap	Treasury Stock Value TreasuryStockValue	103700000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1573200000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1396300000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2341400000	USD
CY2018Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1978900000	USD
CY2016Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1117500000	USD
CY2017Q4	us-gaap	Cumulative Effect Of New Accounting Principle In Period Of Adoption CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	-4100000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	150700000	USD
CY2017	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	55900000	USD
CY2017	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	74400000	USD
CY2017	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	40000000.0	USD
CY2017	us-gaap	Adjustments To Additional Paid In Capital Other AdjustmentsToAdditionalPaidInCapitalOther	-4800000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	69500000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1279900000	USD
CY2018Q4	us-gaap	Cumulative Effect Of New Accounting Principle In Period Of Adoption CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	11400000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	206900000	USD
CY2018	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	48900000	USD
CY2018	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	70800000	USD
CY2018	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	43100000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-36900000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1396300000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	241700000	USD
CY2019	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	54500000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	83100000	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	4900000	USD
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	45700000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4600000	USD
CY2017	us-gaap	Restructuring Reserve Settled Without Cash2 RestructuringReserveSettledWithoutCash2	700000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	24400000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	15100000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1573200000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	241700000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	206900000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	150700000	USD
CY2019	us-gaap	Depreciation Depreciation	100000000.0	USD
CY2018	us-gaap	Depreciation Depreciation	101700000	USD
CY2017	us-gaap	Depreciation Depreciation	94300000	USD
CY2019	us-gaap	Adjustment For Amortization AdjustmentForAmortization	3400000	USD
CY2018	us-gaap	Adjustment For Amortization AdjustmentForAmortization	2700000	USD
CY2017	us-gaap	Adjustment For Amortization AdjustmentForAmortization	2400000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	16100000	USD
CY2019	us-gaap	Restructuring Reserve Settled Without Cash2 RestructuringReserveSettledWithoutCash2	2300000	USD
CY2018	us-gaap	Restructuring Reserve Settled Without Cash2 RestructuringReserveSettledWithoutCash2	2200000	USD
CY2019	us-gaap	Defined Benefit Plan Recognized Net Gain Loss Due To Curtailments DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments	-3500000	USD
CY2018	us-gaap	Defined Benefit Plan Recognized Net Gain Loss Due To Curtailments DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments	0	USD
CY2017	us-gaap	Defined Benefit Plan Recognized Net Gain Loss Due To Curtailments DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments	0	USD
CY2019	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	0	USD
CY2018	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	0	USD
CY2017	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	-11100000	USD
CY2019	us-gaap	Payment For Contingent Consideration Liability Operating Activities PaymentForContingentConsiderationLiabilityOperatingActivities	500000	USD
CY2018	us-gaap	Payment For Contingent Consideration Liability Operating Activities PaymentForContingentConsiderationLiabilityOperatingActivities	600000	USD
CY2017	us-gaap	Payment For Contingent Consideration Liability Operating Activities PaymentForContingentConsiderationLiabilityOperatingActivities	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-800000	USD
CY2018	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-1800000	USD
CY2017	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-1600000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	15300000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	900000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	41700000	USD
CY2019	wst	Pensionand Other Postretirement Benefit Expense Net PensionandOtherPostretirementBenefitExpenseNet	-2600000	USD
CY2018	wst	Pensionand Other Postretirement Benefit Expense Net PensionandOtherPostretirementBenefitExpenseNet	-7900000	USD
CY2017	wst	Pensionand Other Postretirement Benefit Expense Net PensionandOtherPostretirementBenefitExpenseNet	-6900000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	6700000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	5900000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	7000000.0	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	33300000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	43800000	USD
CY2017	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	39700000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	18600000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	7000000.0	USD
CY2017	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	3600000	USD
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CY2018	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	6200000	USD
CY2017	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-300000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	25300000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	400000	USD
CY2017	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	12600000	USD
CY2018	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	0	USD
CY2017	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	18900000	USD
CY2018	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	0	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-9600000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-28300000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	11000000.0	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	367200000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	288600000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	263300000	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
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	130800000	USD
CY2019	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	85100000	USD
CY2017	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	0	USD
CY2019	us-gaap	Cash Divested From Deconsolidation CashDivestedFromDeconsolidation	0	USD
CY2018	us-gaap	Cash Divested From Deconsolidation CashDivestedFromDeconsolidation	0	USD
CY2017	us-gaap	Cash Divested From Deconsolidation CashDivestedFromDeconsolidation	6000000.0	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-2400000	USD
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CY2017	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-3200000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-228000000.0	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-100800000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-133600000	USD
CY2019	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	108500000	USD
CY2018	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	USD
CY2017	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	USD
CY2019	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	136300000	USD
CY2018	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	0	USD
CY2017	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	90000000.0	USD
CY2018	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	0	USD
CY2017	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	0	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	100000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	100000	USD
CY2017	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	34900000	USD
CY2019	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	1200000	USD
CY2018	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	USD
CY2017	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	45100000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	42100000	USD
CY2017	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	39100000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	0	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	0	USD
CY2017	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-700000	USD
CY2019	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	25100000	USD
CY2018	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	27400000	USD
CY2017	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	35700000	USD
CY2019	us-gaap	Proceeds From Other Equity ProceedsFromOtherEquity	5400000	USD
CY2018	us-gaap	Proceeds From Other Equity ProceedsFromOtherEquity	4900000	USD
CY2017	us-gaap	Proceeds From Other Equity ProceedsFromOtherEquity	4400000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	83100000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	70800000	USD
CY2017	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	74400000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-36800000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-80700000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-109000000.0	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-700000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-5600000	USD
CY2017	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	12200000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	101700000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	101500000	USD
CY2017	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	32900000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	337400000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	235900000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	203000000.0	USD
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
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	235900000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	8600000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	8400000	USD
CY2017	us-gaap	Interest Paid Net InterestPaidNet	8000000.0	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	47500000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	42000000.0	USD
CY2017	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	31000000.0	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
CY2017	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	20100000	USD
CY2019Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11800000	USD
CY2018Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11300000	USD
CY2017Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	10400000	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
CY2017	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
CY2019	us-gaap	Use Of Estimates UseOfEstimates	<span style="background-color:rgb(255,255,255, 0.0);color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%;">Use of Estimates:</span><span style="background-color:rgb(255,255,255, 0.0);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>
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	500000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	2000000.0	USD
CY2019Q4	us-gaap	Inventory Raw Materials Net Of Reserves InventoryRawMaterialsNetOfReserves	100900000	USD
CY2018Q4	us-gaap	Inventory Raw Materials Net Of Reserves InventoryRawMaterialsNetOfReserves	90400000	USD
CY2019Q4	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	37400000	USD
CY2018Q4	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	42200000	USD
CY2019Q4	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	97400000	USD
CY2018Q4	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	81900000	USD
CY2019Q4	us-gaap	Inventory Net InventoryNet	235700000	USD
CY2018Q4	us-gaap	Inventory Net InventoryNet	214500000	USD
CY2019	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2019	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2019	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018	us-gaap	Concentration Risk Percentage1 ConcentrationRiskPercentage1	1
CY2018Q4	us-gaap	Transfer Of Financial Assets Accounted For As Sales Cash Proceeds Received For Assets Derecognized Amount TransferOfFinancialAssetsAccountedForAsSalesCashProceedsReceivedForAssetsDerecognizedAmount	5700000	USD
CY2018Q4	wst	Provision For Product Returns ProvisionForProductReturns	11300000	USD
CY2018Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	9100000	USD
CY2019Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	9800000	USD
CY2019	wst	Contractwith Customer Asset Increase Decrease ContractwithCustomerAssetIncreaseDecrease	700000	USD
CY2018Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	33400000	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	34900000	USD
CY2019	us-gaap	Contract With Customer Liability Change In Timeframe Performance Obligation Satisfied Revenue Recognized ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized	-1500000	USD
CY2019	wst	Contract With Customer Liability Increase Decrease Due To Additional Cash Payments ContractWithCustomerLiabilityIncreaseDecreaseDueToAdditionalCashPayments	-114400000	USD
CY2019	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	110400000	USD
CY2019Q1	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	20800000	USD
CY2019	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	2500000	USD
CY2019Q4	us-gaap	Transfer Of Financial Assets Accounted For As Sales Cash Proceeds Received For Assets Derecognized Amount TransferOfFinancialAssetsAccountedForAsSalesCashProceedsReceivedForAssetsDerecognizedAmount	10100000	USD
CY2019	wst	Provision For Product Returns ProvisionForProductReturns	5400000	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	900000	USD
CY2017	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	2700000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	300000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	241700000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	206900000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	150700000	USD
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
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73900000	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
CY2017	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1900000	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
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	75800000	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
CY2017	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	400000	shares
CY2018Q4	us-gaap	Stock Repurchase Program Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased	800000	shares
CY2019	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	800000	shares
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	83100000	USD
CY2019	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	103.89
CY2019Q4	us-gaap	Stock Repurchase Program Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased	848000	shares
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1820100000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1752700000	USD
CY2019	us-gaap	Depreciation Depreciation	100000000.0	USD
CY2018	us-gaap	Depreciation Depreciation	101700000	USD
CY2017	us-gaap	Depreciation Depreciation	94300000	USD
CY2019Q4	us-gaap	Capital Leased Assets Gross CapitalLeasedAssetsGross	0	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	1000000.0	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
CY2019Q4	wst	Lease Operating Lease Terminate Term LeaseOperatingLeaseTerminateTerm	1
CY2019Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	0	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	12900000	USD
CY2019	us-gaap	Short Term Lease Cost ShortTermLeaseCost	800000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	3300000	USD
CY2019	us-gaap	Lease Cost LeaseCost	17000000.0	USD
CY2018	us-gaap	Lease Cost LeaseCost	14500000	USD
CY2017	us-gaap	Lease Cost LeaseCost	13300000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	12500000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	9100000	USD
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P11Y8M12D
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0376
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	12100000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	10400000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	8600000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	7800000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	7300000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	41800000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	88000000.0	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	16000000.0	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	72000000.0	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	13000000.0	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	10500000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	7800000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	6900000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	5500000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	37800000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	81500000	USD
CY2019	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	85100000	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	4900000	USD
CY2019Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	82400000	USD
CY2017	wst	Purchases And Royalty Payments From Equity Method Investees PurchasesAndRoyaltyPaymentsFromEquityMethodInvestees	86700000	USD
CY2018Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	75800000	USD
CY2017Q4	us-gaap	Retained Earnings Undistributed Earnings From Equity Method Investees RetainedEarningsUndistributedEarningsFromEquityMethodInvestees	69900000	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
CY2017	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	2200000	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
CY2019Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	20800000	USD
CY2018Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	12900000	USD
CY2019	wst	Sales To Equity Method Investees SalesToEquityMethodInvestees	9200000	USD
CY2018	wst	Sales To Equity Method Investees SalesToEquityMethodInvestees	9600000	USD
CY2017	wst	Sales To Equity Method Investees SalesToEquityMethodInvestees	8100000	USD
CY2019Q4	us-gaap	Due From Affiliates DueFromAffiliates	1900000	USD
CY2018Q4	us-gaap	Due From Affiliates DueFromAffiliates	1600000	USD
CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	179300000	USD
CY2018Q4	us-gaap	Equity Method Investments EquityMethodInvestments	77800000	USD
CY2019Q4	us-gaap	Cost Method Investments CostMethodInvestments	13400000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	20300000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	107700000	USD
CY2018	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-1900000	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
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired Goodwill And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet	2600000	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
CY2018Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	65200000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	44900000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	3500000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangible Assets Other Than Goodwill BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill	11200000	USD
CY2019	us-gaap	Finite Lived Intangible Assets Foreign Currency Translation Gain Loss FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss	-300000	USD
CY2018	us-gaap	Finite Lived Intangible Assets Foreign Currency Translation Gain Loss FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss	-300000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3400000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2700000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2400000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	4000000.0	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	3500000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	2900000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	2600000	USD
CY2019Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	27500000	USD
CY2018Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	25500000	USD
CY2019Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11800000	USD
CY2018Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	11300000	USD
CY2019Q4	us-gaap	Accrued Sales Commission Current And Noncurrent AccruedSalesCommissionCurrentAndNoncurrent	9700000	USD
CY2018Q4	us-gaap	Accrued Sales Commission Current And Noncurrent AccruedSalesCommissionCurrentAndNoncurrent	5700000	USD
CY2019Q4	us-gaap	Other Postretirement Benefits Payable Current And Noncurrent OtherPostretirementBenefitsPayableCurrentAndNoncurrent	7900000	USD
CY2018Q4	us-gaap	Other Postretirement Benefits Payable Current And Noncurrent OtherPostretirementBenefitsPayableCurrentAndNoncurrent	2300000	USD
CY2019Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	6500000	USD
CY2018Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	5500000	USD
CY2019Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	5900000	USD
CY2018Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	4900000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	3300000	USD
CY2018Q4	us-gaap	Interest Payable Current InterestPayableCurrent	3400000	USD
CY2019Q4	us-gaap	Restructuring Reserve RestructuringReserve	1500000	USD
CY2018Q4	us-gaap	Restructuring Reserve RestructuringReserve	3300000	USD
CY2019Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	17200000	USD
CY2018Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	14700000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	91300000	USD
CY2018Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	76600000	USD
CY2019Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	700000	USD
CY2018Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	600000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	255000000.0	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	196000000.0	USD
CY2019	us-gaap	Interest Expense Debt InterestExpenseDebt	9400000	USD
CY2018	us-gaap	Interest Expense Debt InterestExpenseDebt	9300000	USD
CY2017	us-gaap	Interest Expense Debt InterestExpenseDebt	10500000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Rolling Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths	2300000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	44300000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	2300000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	133800000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	73000000.0	USD
CY2019	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	0	USD
CY2019Q4	us-gaap	Assets Held In Trust Noncurrent AssetsHeldInTrustNoncurrent	11300000	USD
CY2019Q4	us-gaap	Foreign Currency Contract Asset Fair Value Disclosure ForeignCurrencyContractAssetFairValueDisclosure	7700000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	255000000.0	USD
CY2018Q4	us-gaap	Deferred Compensation Liability Classified Noncurrent DeferredCompensationLiabilityClassifiedNoncurrent	9800000	USD
CY2019Q4	us-gaap	Other Assets Fair Value Disclosure OtherAssetsFairValueDisclosure	100000	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	Deferred Compensation Liability Classified Noncurrent DeferredCompensationLiabilityClassifiedNoncurrent	12800000	USD
CY2019Q4	us-gaap	Foreign Currency Contracts Liability Fair Value Disclosure ForeignCurrencyContractsLiabilityFairValueDisclosure	300000	USD
CY2019Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	17800000	USD
CY2018Q4	us-gaap	Assets Held In Trust Noncurrent AssetsHeldInTrustNoncurrent	8700000	USD
CY2018Q4	us-gaap	Foreign Currency Contract Asset Fair Value Disclosure ForeignCurrencyContractAssetFairValueDisclosure	6500000	USD
CY2018Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	15200000	USD
CY2018Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	1700000	USD
CY2018Q4	us-gaap	Foreign Currency Contracts Liability Fair Value Disclosure ForeignCurrencyContractsLiabilityFairValueDisclosure	200000	USD
CY2018Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	11700000	USD
CY2017Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	4900000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-2600000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements	600000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	1700000	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
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	3300000	USD
CY2019Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	263300000	USD
CY2018Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	192600000	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	196000000.0	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-117300000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-37700000	USD
CY2018	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-800000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-36900000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-154200000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	8400000	USD
CY2019	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	3800000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4600000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-149600000	USD
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	3119314	shares
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	24400000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	15100000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16100000	USD
CY2019Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	21200000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y7M6D
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
CY2016Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	4500000	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
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	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
CY2017	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1500000	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
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	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
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	3500000	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
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	1900000	shares
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
CY2016Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	38.11
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
CY2017	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	84.09
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	46.42
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	35.95
CY2017	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	26.15
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
CY2017	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	60.92
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
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
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	35.44
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P6Y1M6D
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P5Y
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	227800000	USD
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue	158600000	USD
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
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	18.08
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
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	91700000	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
CY2017	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	6700000	USD
CY2019Q4	wst	Cash Settled Stock Appreciation R Ights Outstanding CashSettledStockAppreciationRIghtsOutstanding	23833	shares
CY2019Q4	wst	Stock Settled Stock Appreciation Rights Outstanding StockSettledStockAppreciationRightsOutstanding	12160	shares
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	15600000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	6500000	USD
CY2017	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	5700000	USD
CY2019	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	2600000	USD
CY2019	wst	Defined Benefit Plan Ultimate Health Care Cost Trend Rate Net Periodic Benefit Cost DefinedBenefitPlanUltimateHealthCareCostTrendRateNetPeriodicBenefitCost	0.0500
CY2019Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	283900000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	263000000.0	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	22300000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	14800000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	17000000.0	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	15200000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	15400000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	73800000	USD
CY2019Q4	wst	Defined Benefit Plan Expected Future Benefit Payments DefinedBenefitPlanExpectedFutureBenefitPayments	158500000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Employer Contributions Next Fiscal Year DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear	700000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Health Care Cost Trend Rate Assumed Next Fiscal Year DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear	0.0625
CY2019Q4	us-gaap	Defined Benefit Plan Ultimate Health Care Cost Trend Rate1 DefinedBenefitPlanUltimateHealthCareCostTrendRate1	0.0500
CY2019	wst	Defined Benefit Plan Health Care Cost Trend Rate Assumed For Next Fiscal Year Net Periodic Benefit Cost DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearNetPeriodicBenefitCost	0.0625
CY2019Q4	us-gaap	Defined Benefit Plan Weighted Average Asset Allocations DefinedBenefitPlanWeightedAverageAssetAllocations	1
CY2018Q4	us-gaap	Defined Benefit Plan Weighted Average Asset Allocations DefinedBenefitPlanWeightedAverageAssetAllocations	1
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	244100000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	214500000	USD
CY2019	us-gaap	Severance Costs1 SeveranceCosts1	2600000	USD
CY2018	us-gaap	Severance Costs1 SeveranceCosts1	3100000	USD
CY2017	us-gaap	Severance Costs1 SeveranceCosts1	0	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	300000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	2200000	USD
CY2017	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2019	us-gaap	Other Restructuring Costs OtherRestructuringCosts	2000000.0	USD
CY2018	us-gaap	Other Restructuring Costs OtherRestructuringCosts	3800000	USD
CY2017	us-gaap	Other Restructuring Costs OtherRestructuringCosts	0	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
CY2017	us-gaap	Restructuring And Related Cost Incurred Cost RestructuringAndRelatedCostIncurredCost	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
CY2017	us-gaap	Foreign Currency Transaction Loss Before Tax ForeignCurrencyTransactionLossBeforeTax	0	USD
CY2019	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	0	USD
CY2018	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	0	USD
CY2017	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	-11100000	USD
CY2019	wst	Developmentandlicensingincome Developmentandlicensingincome	900000	USD
CY2018	wst	Developmentandlicensingincome Developmentandlicensingincome	900000	USD
CY2017	wst	Developmentandlicensingincome Developmentandlicensingincome	10600000	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
CY2017	us-gaap	Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1	-2400000	USD
CY2019	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	4900000	USD
CY2018	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	4800000	USD
CY2017	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	-3900000	USD
CY2019	wst	Other Income Expense OtherIncomeExpense	2500000	USD
CY2019	us-gaap	Gain Loss On Sales Of Assets And Asset Impairment Charges GainLossOnSalesOfAssetsAndAssetImpairmentCharges	1100000	USD
CY2018	wst	Other Income Expense OtherIncomeExpense	-1900000	USD
CY2017	wst	Other Income Expense OtherIncomeExpense	-2000000.0	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
CY2017	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	-11100000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Before Tax ForeignCurrencyTransactionGainBeforeTax	5600000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Unrealized ForeignCurrencyTransactionGainLossUnrealized	-5500000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3900000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3200000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1600000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	800000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	400000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	500000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	500000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	5000000.0	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3900000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	200000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	5000000.0	USD
CY2019Q4	us-gaap	Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit	500000	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
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	96500000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	130600000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	107800000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	125900000	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
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	222400000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	10800000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	2100000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	2100000	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
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	100000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	30500000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	35100000	USD
CY2017	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	37000000.0	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	43700000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	40500000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	39200000	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
CY2017	wst	Deferred Federal State And Local Income Tax Expense Benefit DeferredFederalStateAndLocalIncomeTaxExpenseBenefit	41800000	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
CY2017	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-100000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	15300000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	900000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	41700000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	59000000.0	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	41400000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	80900000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	21900000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2000000.0	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	18400000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	2800000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	10500000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	25600000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	27200000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	9200000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	11400000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	15900000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	16000000.0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	43600000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	51500000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	37900000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	31300000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	6300000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	6600000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	900000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	45100000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	39900000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	-1500000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	11600000	USD
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
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
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
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.045
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.005
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
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.002
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0.004
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0.002
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0.001
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.014
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CY2017	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.002
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.009
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.008
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CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.202
CY2017	wst	Effective Income Tax Rate Reconciliation Undistributed Earningsof Subsidiaries Percentage EffectiveIncomeTaxRateReconciliationUndistributedEarningsofSubsidiariesPercentage	0.044
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CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.060
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.141
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
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.159
CY2019	wst	Effective Income Tax Rate Reconciliation Undistributed Earningsof Subsidiaries Percentage EffectiveIncomeTaxRateReconciliationUndistributedEarningsofSubsidiariesPercentage	-0.002
CY2018	wst	Effective Income Tax Rate Reconciliation Undistributed Earningsof Subsidiaries Percentage EffectiveIncomeTaxRateReconciliationUndistributedEarningsofSubsidiariesPercentage	-0.013
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Equity In Earnings Losses Of Unconsolidated Subsidiary EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary	0
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Equity In Earnings Losses Of Unconsolidated Subsidiary EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary	0.017
CY2019	wst	Effective Income Tax Rate Reconciliation General Business Credits And Section199 Deduction EffectiveIncomeTaxRateReconciliationGeneralBusinessCreditsAndSection199Deduction	0
CY2018	wst	Effective Income Tax Rate Reconciliation General Business Credits And Section199 Deduction EffectiveIncomeTaxRateReconciliationGeneralBusinessCreditsAndSection199Deduction	0
CY2017	wst	Effective Income Tax Rate Reconciliation General Business Credits And Section199 Deduction EffectiveIncomeTaxRateReconciliationGeneralBusinessCreditsAndSection199Deduction	-0.006
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.010
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.002
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.002
CY2017	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	96700000	USD
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.172
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.364
CY2019	us-gaap	Other Income Tax Expense Benefit Continuing Operations OtherIncomeTaxExpenseBenefitContinuingOperations	-300000	USD
CY2018	wst	Tax Cutsand Jobs Actof2017 Incomplete Accounting Changein Tax Rate Provisional Income Tax Expense TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateProvisionalIncomeTaxExpense	-2500000	USD
CY2017	wst	Tax Cutsand Jobs Actof2017 Incomplete Accounting Changein Tax Rate Provisional Income Tax Expense TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateProvisionalIncomeTaxExpense	48800000	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
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CY2017	wst	Tax Cutsand Jobs Actof2017 Incomplete Accounting Deferred Tax Liability Provisional Income Tax Expense TaxCutsandJobsActof2017IncompleteAccountingDeferredTaxLiabilityProvisionalIncomeTaxExpense	11400000	USD
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CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Income Tax Expense TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpense	20400000	USD
CY2017	us-gaap	Tax Cuts And Jobs Act Of2017 Incomplete Accounting Transition Tax For Accumulated Foreign Earnings Provisional Income Tax Expense TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense	27900000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Measurement Period Adjustment Increase Decrease In Effective Tax Rate TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncreaseDecreaseInEffectiveTaxRate	-0.0145
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	15500000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Foreign DeferredTaxAssetsOperatingLossCarryforwardsForeign	6400000	USD
CY2019Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	214200000	USD
CY2018	us-gaap	Revenues Revenues	1717400000	USD
CY2017	us-gaap	Revenues Revenues	1599100000	USD
CY2019Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance Sheet Amount UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount	249100000	USD
CY2018Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On First Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary	61300000	USD
CY2019Q4	us-gaap	Business Combination Contingent Consideration Arrangements Range Of Outcomes Value Low BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow	0	USD
CY2019Q4	us-gaap	Business Combination Contingent Consideration Arrangements Range Of Outcomes Value High BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh	3700000	USD
CY2019	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2019	us-gaap	Revenues Revenues	1839900000	USD
CY2019	us-gaap	Segment Reporting Disclosure Of Major Customers SegmentReportingDisclosureOfMajorCustomers	10
CY2019	us-gaap	Revenues Revenues	1839900000	USD
CY2019	us-gaap	Gross Profit GrossProfit	605700000	USD
CY2018	us-gaap	Revenues Revenues	1717400000	USD
CY2017	us-gaap	Revenues Revenues	1599100000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	839300000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	822000000.0	USD
CY2017Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	855000000.0	USD
CY2019	us-gaap	Revenues Revenues	1839900000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	296600000	USD
CY2019	us-gaap	Interest Expense InterestExpense	8500000	USD
CY2019	us-gaap	Investment Income Net InvestmentIncomeNet	3800000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-100000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	291800000	USD
CY2019Q4	us-gaap	Assets Assets	2341400000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	126400000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	103400000	USD
CY2018	us-gaap	Revenues Revenues	1717400000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	240300000	USD
CY2018	us-gaap	Interest Expense InterestExpense	8400000	USD
CY2018	us-gaap	Investment Income Net InvestmentIncomeNet	2100000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	6700000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	240700000	USD
CY2018Q4	us-gaap	Assets Assets	1978900000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	104700000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	104400000	USD
CY2017	us-gaap	Revenues Revenues	1599100000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	225800000	USD
CY2017	us-gaap	Interest Expense InterestExpense	7800000	USD
CY2017	us-gaap	Investment Income Net InvestmentIncomeNet	1300000	USD
CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	3100000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	222400000	USD
CY2017Q4	us-gaap	Assets Assets	1862800000	USD
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	130800000	USD
CY2018	us-gaap	Gross Profit GrossProfit	545400000	USD
CY2018	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	1100000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	241700000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	206900000	USD
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.80
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.74
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
CY2018Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	18000000.0	USD
CY2016Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	19100000	USD
CY2017	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	2300000	USD
CY2017	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	0	USD
CY2017Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	21400000	USD

Files In Submission

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$WST
WEST PHARMACEUTICAL SERVICES INC Stock $wst

2019 Form 10-K Financial Statement

#000010577020000015 Filed on February 24, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WST WEST PHARMACEUTICAL SERVICES INC Stock $wst

2019 Form 10-K Financial Statement

#000010577020000015 Filed on February 24, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WST
WEST PHARMACEUTICAL SERVICES INC Stock $wst