EQUITY (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 255,474
Net earnings			60,670
Other comprehensive income	$ (1,917)	$ 674	3,427	$ (9,443)
Exercise of stock options (202,500 shares)			2,772
Shares issued to Board of Directors in lieu of cash (3,276 shares)			75
Stock-based compensation			7,246
Cash dividend ($0.45 per share)			(22,437)
Purchase of common stock (211,714 shares)			(4,503)
Ending Balance	302,724		$ 302,724
Exercise of stock options (in shares)			202,500
Shares issued to Board of Directors in lieu of cash (in shares)			3,276
Cash dividend (in dollars per share)			$ 0.45
Purchase of common stock (in shares)			211,714
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 488
Exercise of stock options (202,500 shares)			2
Shares issued under stock incentive plan (313,632)			3
Purchase of common stock (211,714 shares)			(2)
Ending Balance	491		$ 491
Shares issued under stock incentive plan (in shares)			313,632
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 47,165
Exercise of stock options (202,500 shares)			2,770
Shares issued under stock incentive plan (313,632)			(3)
Shares issued to Board of Directors in lieu of cash (3,276 shares)			75
Stock-based compensation			7,380
Purchase of common stock (211,714 shares)			(4,501)
Ending Balance	52,886		52,886
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			244,947
Net earnings			60,642
Cash dividend ($0.45 per share)			(22,437)
Ending Balance	283,018		283,018
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			(37,318)
Other comprehensive income			3,427
Ending Balance	(33,891)		(33,891)
Total Knoll, Inc. Stockholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			255,282
Net earnings			60,642
Other comprehensive income			3,427
Exercise of stock options (202,500 shares)			2,772
Shares issued to Board of Directors in lieu of cash (3,276 shares)			75
Stock-based compensation			7,246
Cash dividend ($0.45 per share)			(22,437)
Purchase of common stock (211,714 shares)			(4,503)
Ending Balance	302,504		302,504
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			192
Net earnings			28
Ending Balance	$ 220		$ 220