EQUITY (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Change in equity attributable to Knoll, Inc. stockholders and noncontrolling interests:
Balance, as of December 31, 2014			$ 213,218
Total comprehensive income:
Net earnings (losses) attributable to Knoll, Inc. stockholders and noncontrolling interests			34,657	$ 18,673
Total other comprehensive income (loss), net of tax	$ 1,500	$ 3,794	(10,117)	$ 39
Other changes in equity:
Purchase of common stock for treasury			(6,067)
Cash dividends declared			(11,874)
Proceeds from the issuance of common stock			4,421
Stock-based compensation			3,574
Excess tax benefit from the exercise of stock options and vesting of equity awards			979
Balance, as of June 30, 2015	228,791		228,791
Equity Attributable to Knoll Inc., Stockholders
Change in equity attributable to Knoll, Inc. stockholders and noncontrolling interests:
Balance, as of December 31, 2014			213,011
Total comprehensive income:
Net earnings (losses) attributable to Knoll, Inc. stockholders and noncontrolling interests			34,682
Total other comprehensive income (loss), net of tax			(10,117)
Other changes in equity:
Purchase of common stock for treasury			(6,067)
Cash dividends declared			(11,874)
Proceeds from the issuance of common stock			4,421
Stock-based compensation			3,574
Excess tax benefit from the exercise of stock options and vesting of equity awards			979
Balance, as of June 30, 2015	228,609		228,609
Noncontrolling Interests
Change in equity attributable to Knoll, Inc. stockholders and noncontrolling interests:
Balance, as of December 31, 2014			207
Total comprehensive income:
Net earnings (losses) attributable to Knoll, Inc. stockholders and noncontrolling interests			(25)
Total other comprehensive income (loss), net of tax			0
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
Excess tax benefit from the exercise of stock options and vesting of equity awards			0
Balance, as of June 30, 2015	$ 182		$ 182