CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net sales	$ 266,498	$ 229,601
Cost of sales	171,189	153,003
Gross profit	95,309	76,598
Selling, general, and administrative expenses	73,010	64,722
Restructuring charges	0	592
Operating profit	22,299	11,284
Interest expense	1,885	1,671
Other (income) expense, net	(7,157)	(2,504)
Income before income tax expense	27,571	12,117
Income tax expense	10,136	4,285
Net earnings	17,435	7,832
Net earnings (loss) attributable to noncontrolling interests	(8)	6
Net earnings attributable to Knoll, Inc. stockholders	17,443	7,826
Net earnings per common share attributable to Knoll, Inc. stockholders:
Basic (in dollars per share)	$ 0.37	$ 0.17
Diluted (in dollars per share)	$ 0.36	$ 0.16
Dividends per share (in dollars per share)	$ 0.12	$ 0.12
Weighted-average number of common shares outstanding:
Basic	47,647,961	47,200,099
Diluted	48,353,047	48,048,994
Net earnings	17,435	7,832
Other comprehensive income (loss):
Foreign currency translation adjustment	(12,999)	(3,819)
Pension and other post-retirement liability adjustment, net of tax	1,382	64
Total other comprehensive loss, net of tax	(11,617)	(3,755)
Total comprehensive income	5,818	4,077
Comprehensive income (loss) attributable to noncontrolling interests	(8)	6
Comprehensive income attributable to Knoll, Inc. stockholders	$ 5,826	$ 4,071