CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net sales		$ 268,622	$ 265,943	$ 535,120	$ 495,544
Cost of sales		167,431	168,669	338,620	321,672
Gross profit		101,191	97,274	196,500	173,872
Selling, general, and administrative expenses		72,936	74,833	145,946	139,555
Restructuring charges		0	203	0	795
Operating profit	[1]	28,255	22,238	50,554	33,522
Interest expense		1,851	1,944	3,736	3,615
Other expense (income), net		200	2,700	(6,957)	196
Income before income tax expense		26,204	17,594	53,775	29,711
Income tax expense		8,982	6,753	19,118	11,038
Net earnings		17,222	10,841	34,657	18,673
Net losses attributable to noncontrolling interests		(17)	(14)	$ (25)	(8)
Net earnings attributable to Knoll, Inc. stockholders		$ 17,239	$ 10,855		$ 18,681
Net earnings per common share attributable to Knoll, Inc. stockholders:
Basic (in dollars per share)		$ 0.36	$ 0.23	$ 0.73	$ 0.40
Diluted (in dollars per share)		0.36	0.23	0.72	0.39
Dividends per share (in dollars per share)		$ 0.12	$ 0.12	$ 0.24	$ 0.24
Weighted-average number of common shares outstanding:
Basic (in shares)		47,760,961	47,365,780	47,705,222	47,283,396
Diluted (in shares)		48,509,546	47,974,559	48,445,060	48,012,233
Net earnings		$ 17,222	$ 10,841	$ 34,657	$ 18,673
Other comprehensive income (loss):
Foreign currency translation adjustment		118	3,730	(12,881)	(89)
Pension and other post-retirement liability adjustment, net of tax		1,382	64	2,764	128
Total other comprehensive income (loss), net of tax		1,500	3,794	(10,117)	39
Total comprehensive income		18,722	14,635	24,540	18,712
Comprehensive losses attributable to noncontrolling interests			(14)		(8)
Comprehensive income attributable to Knoll, Inc. stockholders		$ 18,739	$ 14,649	$ 24,565	$ 18,720

[1] The Company does not allocate interest expense or other (income) expense, net to the reportable segments.