CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Sales	$ 292,097	$ 263,588	$ 871,426	$ 798,708
Cost of sales	179,296	162,381	536,797	501,001
Gross profit	112,801	101,207	334,629	297,707
Selling, general, and administrative expenses	77,598	72,062	234,103	218,008
Restructuring and other charges	0	441	0	441
Operating profit	35,203	28,704	100,526	79,258
Interest expense	1,296	1,650	4,157	5,386
Other expense (income), net	681	(1,757)	3,470	(8,714)
Income before income tax expense	33,226	28,811	92,899	82,586
Income tax expense	11,608	10,950	32,229	30,068
Net earnings	21,618	17,861	60,670	52,518
Net earnings attributable to noncontrolling interests	11	28	28	3
Net earnings attributable to Knoll, Inc. stockholders	$ 21,607	$ 17,833	$ 60,642	$ 52,515
Net earnings per common share attributable to Knoll, Inc. stockholders:
Basic (in dollars per share)	$ 0.45	$ 0.37	$ 1.26	$ 1.10
Diluted (in dollars per share)	0.44	0.37	1.24	1.08
Dividends per share (in dollars per share)	$ 0.15	$ 0.12	$ 0.45	$ 0.36
Weighted-average number of common shares outstanding:
Basic (in shares)	48,053,836	47,764,462	48,000,386	47,725,186
Diluted (in shares)	48,845,553	48,487,623	48,765,607	48,441,129
Other comprehensive (loss) income:
Pension and other postretirement liability adjustment, net of tax	$ (136)	$ 4,902	$ (408)	$ 7,666
Foreign currency translation adjustment	(1,781)	(4,228)	3,835	(17,109)
Total other comprehensive (loss) income, net of tax	(1,917)	674	3,427	(9,443)
Total comprehensive income	19,701	18,535	64,097	43,075
Comprehensive income attributable to noncontrolling interests	11	28	28	3
Comprehensive income attributable to Knoll, Inc. stockholders	$ 19,690	$ 18,507	$ 64,069	$ 43,072