The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Value of stock issued pursuant to acquisitions during the period.

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Affiliated Companies (Details) - USD ($) $ in Millions	12 Months Ended
Affiliated Companies (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 01, 2019
Schedule of Equity Method Investments [Line Items]
Purchase in investment in affiliated companies in cash	$ 85.1	$ 0.0	$ 0.0
Purchase of investment in affiliated companies	$ 4.9
The West Company Mexico, S.A. de C.V. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest	49.00%
Aluplast S.A. de C.V. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest	49.00%
Pharma Tap S.A de C.V. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest	49.00%
Pharma Rubber S.A. de C.V. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest	49.00%
Daikyo Seiko, Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest	49.00%	25.00%		49.00%
I&W Pharma Group LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest	49.00%