CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net sales	$ 263,588	$ 268,297	$ 798,708	$ 763,841
Cost of sales	162,381	173,335	501,001	495,007
Gross profit	101,207	94,962	297,707	268,834
Selling, general, and administrative expenses	72,062	71,647	218,008	211,202
Restructuring charges	441	0	441	795
Operating profit	28,704	23,315	79,258	56,837
Interest expense	1,650	1,899	5,386	5,514
Other (income), net	(1,757)	(3,294)	(8,714)	(3,098)
Income before income tax expense	28,811	24,710	82,586	54,421
Income tax expense	10,950	9,113	30,068	20,151
Net earnings	17,861	15,597	52,518	34,270
Net gains (losses) attributable to noncontrolling interests	28	(31)	3	(39)
Net earnings attributable to Knoll, Inc. stockholders	$ 17,833	$ 15,628	$ 52,515	$ 34,309
Net earnings per common share attributable to Knoll, Inc. stockholders:
Basic (in dollars per share)	$ 0.37	$ 0.33	$ 1.10	$ 0.73
Diluted (in dollars per share)	0.37	0.33	1.08	0.71
Dividends per share (in dollars per share)	$ 0.12	$ 0.12	$ 0.36	$ 0.36
Weighted-average number of common shares outstanding:
Basic (in shares)	47,764,462	47,376,605	47,725,186	47,314,810
Diluted (in shares)	48,487,623	48,072,632	48,441,129	48,032,710
Net earnings	$ 17,861	$ 15,597	$ 52,518	$ 34,270
Other comprehensive income (loss):
Foreign currency translation adjustment	(4,228)	(7,488)	(17,109)	(7,577)
Pension and other post-retirement curtailment gain, net of tax	4,549	0	4,549	0
Pension and other post-retirement liability adjustment, net of tax	353	64	3,117	191
Total other comprehensive income (loss), net of tax	674	(7,424)	(9,443)	(7,386)
Total comprehensive income	18,535	8,173	43,075	26,884
Comprehensive gains (losses) attributable to noncontrolling interests		(31)		(39)
Comprehensive income attributable to Knoll, Inc. stockholders	$ 18,507	$ 8,204	$ 43,072	$ 26,923