Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net sales	$ 1,090.8	$ 1,001.0	$ 1,137.6
Cost of sales	652.8	593.2	675.9
Gross profit	438.0	407.8	461.7
Selling and administrative expense	321.9	314.0	357.2
Research and development expense	32.2	30.1	32.7
Gain on sale of business	(9.8)	0.0	0.0
Operating income	93.7	63.7	71.8
Interest expense, net	(7.3)	(17.4)	(17.8)
Net foreign currency transaction loss	(0.7)	(5.3)	(0.7)
Loss on extinguishment of debt	11.3	0.0	0.0
Other (expense) income, net	(0.3)	0.1	0.7
Income before income taxes	74.1	41.1	54.0
Income tax expense	9.2	7.4	8.1
Net income including noncontrolling interest	64.9	33.7	45.9
Net income attributable to noncontrolling interest	0.0	0.0	0.1
Net income attributable to Tennant Company	$ 64.9	$ 33.7	$ 45.8
Net income attributable to Tennant Company per share:
Basic (in dollars per share)	$ 3.51	$ 1.84	$ 2.53
Diluted (in dollars per share)	$ 3.44	$ 1.81	$ 2.48
Weighted average shares outstanding:
Basic (in shares)	18,499,674	18,349,724	18,118,486
Diluted (in shares)	18,849,217	18,635,002	18,453,145