Background and Basis of Presentation - Marketable Securities (Details) $ in Millions	Sep. 30, 2019 USD ($)
United States
Marketable securities
Cost of marketable securities	$ 4.3
United States \| Fair Value \| Level 1 \| Other Assets
Marketable securities
Fair value of marketable securities	3.9
Germany \| Pension Benefits
Held to maturity
Investments restricted to the payment of post-retirement employee benefits	1.8
Germany \| Other Assets \| Pension Benefits
Held to maturity
Investments restricted to the payment of post-retirement employee benefits	1.2
Germany \| Prepaid Expenses and Other Current Assets \| Pension Benefits
Held to maturity
Investments restricted to the payment of post-retirement employee benefits	$ 0.6

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Section S99
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant