EQUITY (Details) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013
Change in equity attributable to Knoll, Inc. stockholders and noncontrolling interests:
Balance, as of December 31, 2013			$ 228,442,000	$ 228,442,000
Noncontrolling interest recognized in the acquisition of HOLLY HUNT				218,000
Total comprehensive income:
Net earnings				34,654,000	22,512,000
Pension and other post retirement liability adjustment	64,000	913,000		191,000	2,782,000
Foreign currency translation adjustment	(7,488,000)	4,047,000		(7,577,000)	(3,164,000)
Total other comprehensive income (loss), net of tax	(7,424,000)	4,960,000		(7,386,000)	(382,000)
Total comprehensive income	8,198,000	13,510,000		27,268,000	22,130,000
Other changes in equity:
Cash dividends declared				(17,585,000)
Proceeds from the issuance of common stock				2,788,000
Stock-based compensation				5,869,000
Other				(878,000)
Balance, as of September 30, 2014	239,710,000			239,710,000
Cash dividend (in dollars per share)
Equity Attributable to Knoll Inc., Stockholders [Member]
Change in equity attributable to Knoll, Inc. stockholders and noncontrolling interests:
Balance, as of December 31, 2013			228,442,000	228,442,000
Noncontrolling interest recognized in the acquisition of HOLLY HUNT				0
Total comprehensive income:
Net earnings				34,693,000
Pension and other post retirement liability adjustment				191,000
Foreign currency translation adjustment				(7,577,000)
Total other comprehensive income (loss), net of tax				(7,386,000)
Total comprehensive income				27,307,000
Other changes in equity:
Purchase of common stock for treasury				(6,412,000)
Cash dividends declared				(17,585,000)
Proceeds from the issuance of common stock				2,788,000
Stock-based compensation				5,869,000
Other				(878,000)
Balance, as of September 30, 2014	239,531,000			239,531,000
Noncontrolling Interests [Member]
Change in equity attributable to Knoll, Inc. stockholders and noncontrolling interests:
Balance, as of December 31, 2013			0	0
Noncontrolling interest recognized in the acquisition of HOLLY HUNT				218,000
Total comprehensive income:
Net earnings				(39,000)
Pension and other post retirement liability adjustment				0
Foreign currency translation adjustment				0
Total other comprehensive income (loss), net of tax				0
Total comprehensive income				(39,000)
Other changes in equity:
Purchase of common stock for treasury				0
Cash dividends declared				0
Proceeds from the issuance of common stock				0
Stock-based compensation				0
Other				0
Balance, as of September 30, 2014	$ 179,000			$ 179,000