Income Taxes - Schedule of operating loss carryovers (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 149.5	$ 191.0
Decrease in valuation allowance	23.1
United States
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	23.0
Other countries
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 126.5

The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 30
-Paragraph 5
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=109238119&loc=d3e30536-109315

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

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Period Type:	instant