CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Sales	$ 256,820	$ 284,629
Cost of sales	161,146	176,865
Gross profit	95,674	107,764
Selling, general, and administrative expenses	72,640	75,915
Operating profit	23,034	31,849
Interest expense	1,671	1,554
Other expense, net	203	2,604
Income before income tax expense	21,160	27,691
Income tax expense	5,764	10,280
Net earnings	15,396	17,411
Net (loss) earnings attributable to noncontrolling interests	(8)	11
Net earnings attributable to Knoll, Inc. stockholders	$ 15,404	$ 17,400
Net earnings per common share attributable to Knoll, Inc. stockholders:
Basic (in dollars per share)	$ 0.32	$ 0.36
Diluted (in dollars per share)	0.31	0.36
Dividends per share (in dollars per share)	$ 0.15	$ 0.15
Weighted-average number of common shares outstanding:
Basic (in shares)	48,456,225	47,904,593
Diluted (in shares)	49,382,892	48,594,395
Other comprehensive income (loss):
Pension and other postretirement liability adjustment, net of tax	$ (137)	$ 138
Foreign currency translation adjustment	480	4,049
Total other comprehensive income (loss), net of tax	343	4,187
Total comprehensive income	15,739	21,598
Comprehensive (loss) income attributable to noncontrolling interests	(8)	11
Comprehensive income attributable to Knoll, Inc. stockholders	$ 15,747	$ 21,587