ACQUISITIONS - Pro forma Summary Financial Information (Details) (Holly Hunt Enterprises, Inc [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Holly Hunt Enterprises, Inc [Member]
Business Acquisition, Pro Forma Information [Abstract]
Pro forma net sales	$ 240,428	$ 771,246	$ 699,994
Pro forma net earnings attributable to Knoll, Inc stockholders	$ 8,954	$ 35,176	$ 23,988

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration