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Significant Accounting Policies Trade Receivables and Allowance for Doubtful Accounts (Details) $ in Millions | Dec. 31, 2018 USD ($) d | Dec. 31, 2017 USD ($)
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Significant Accounting Policies [Abstract] |  |
Customer credit terms (in days) | d | 30 |
Allowance for Doubtful Accounts Receivable, Current | $ | $ 0.9 | $ 1.5

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- Definition customer credit terms days + References No definition available. + Details
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- Definition Significant Accounting Policies [Abstract] + References No definition available. + Details
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- Definition A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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