Commitments and Contingencies - (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Accrued liabilities for other litigation, claims, other disputes and governmental proceedings	$ 1.3	$ 1.3
Guarantor Obligations [Line Items]
Letters of credit outstanding	0.1	0.1
Purchase obligations	24.8
Surety bonds \| Certain development projects
Guarantor Obligations [Line Items]
Commitment obligations	$ 8.6	$ 8.6

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

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Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

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