EQUITY (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 309,469
Net earnings	15,396
Other comprehensive income	343	$ 4,187
Exercise of stock options (22,500 shares)	472
Shares issued under stock incentive plan (668,899)	4
Shares issued to Board of Directors in lieu of cash (1,942 shares)	50
Stock-based compensation	3,344
Cash dividend ($0.15 per share)	(7,553)
Purchase of common stock (410,616 shares)	(10,348)
Ending Balance	$ 311,177
Exercise of stock options (in shares)	22,500
Shares issued under stock incentive plans (in shares)	668,899
Shares issued to Board of Directors in lieu of cash (in shares)	1,942
Cash dividend (in dollars per share)	$ 0.15
Purchase of common stock (in shares)	410,616
Total Knoll, Inc. Stockholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 309,247
Net earnings	15,404
Other comprehensive income	343
Exercise of stock options (22,500 shares)	472
Shares issued under stock incentive plan (668,899)	4
Shares issued to Board of Directors in lieu of cash (1,942 shares)	50
Stock-based compensation	3,344
Cash dividend ($0.15 per share)	(7,553)
Purchase of common stock (410,616 shares)	(10,348)
Ending Balance	310,963
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	491
Shares issued under stock incentive plan (668,899)	7
Purchase of common stock (410,616 shares)	(4)
Ending Balance	494
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	55,148
Exercise of stock options (22,500 shares)	472
Shares issued under stock incentive plan (668,899)	(3)
Shares issued to Board of Directors in lieu of cash (1,942 shares)	50
Stock-based compensation	3,344
Purchase of common stock (410,616 shares)	(10,344)
Ending Balance	48,667
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	297,011
Net earnings	15,404
Cash dividend ($0.15 per share)	(7,553)
Ending Balance	304,862
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(43,403)
Other comprehensive income	343
Ending Balance	(43,060)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	222
Net earnings	(8)
Ending Balance	$ 214