ACQUISITION - Pro Forma Information (Details) - Muuto Acquisition $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($)
Business Acquisition [Line Items]
Pro forma sales	$ 300.7
Pro forma net earnings attributable to Knoll, Inc. stockholders	$ 17.6

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(3)
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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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