COVER - shares	9 Months Ended
	Sep. 30, 2019	Nov. 07, 2019
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-12907
Entity Registrant Name	KNOLL, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3873847
Entity Address, Address Line One	1235 Water Street
Entity Address, City or Town	East Greenville
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	18041
City Area Code	215
Local Phone Number	679-7991
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NYSE
Trading Symbol	KNL
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001011570
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		49,774,598
Restricted Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		896,181