Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 09, 2019
Document Information [Line Items]
Entity Registrant Name	KNOLL INC
Entity Central Index Key	0001011570
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		49,757,728
Restricted stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		913,273