CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Sales	$ 284,629	$ 266,498
Cost of sales	176,865	171,189
Gross profit	107,764	95,309
Selling, general, and administrative expenses	75,915	73,010
Operating profit	31,849	22,299
Interest expense	1,554	1,885
Other expense (income), net	2,604	(7,157)
Income before income tax expense	27,691	27,571
Income tax expense	10,421	10,136
Net earnings	17,270	17,435
Net earnings (loss) attributable to noncontrolling interests	11	(8)
Net earnings attributable to Knoll, Inc. stockholders	$ 17,259	$ 17,443
Net earnings per common share attributable to Knoll, Inc. stockholders:
Basic (in dollars per share)	$ 0.36	$ 0.37
Diluted (in dollars per share)	0.36	0.36
Dividends per share (in dollars per share)	$ 0.15	$ 0.12
Weighted-average number of common shares outstanding:
Basic (in shares)	47,904,593	47,647,961
Diluted (in shares)	48,570,895	48,353,047
Other comprehensive income (loss):
Pension and other postretirement liability adjustment, net of tax	$ 138	$ 1,382
Foreign currency translation adjustment	4,049	(12,999)
Total other comprehensive income (loss), net of tax	4,187	(11,617)
Comprehensive income attributable to Knoll, Inc. stockholders	21,457	5,818
Comprehensive income (loss) attributable to noncontrolling interests	11	(8)
Comprehensive income attributable to Knoll, Inc. stockholders	$ 21,446	$ 5,826