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Note 10 - Revenue 1 (Details Textual) - USD ($) $ in Millions |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jul. 27, 2018 | Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017
Increase (Decrease) in Revenue from Contract with Customers, Including Assessed Tax |  | $ (0.2) | $ 0.3 | $ 0.5 | $ (0.3)
Contract with Customer, Liability, Revenue Recognized |  | 0.1 | $ 0.9 | 2.2 | $ 1.7
Revenue, Remaining Performance Obligation, Amount |  | $ 100.2 |  | $ 100.2 |
Ameron Water Transmission Group, LLC [Member] |  |  |  |  |
Contract with Customer, Asset, Increase (Decrease) for Contract Acquired in Business Combination | $ 11.9 |  |  |  |
Contract with Customer, Liability, Increase (Decrease) for Contract Acquired in Business Combination | $ 0.1 |  |  |  |

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- Definition The increase (decrease) during the period of the amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. + References No definition available. + Details
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- Definition Amount of increase (decrease) in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, from business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130551-203045 + Details
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