Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Sales	$ 1,001.0	$ 1,137.6	$ 1,123.5
Cost of Sales	593.2	675.9	678.5
Gross Profit	407.8	461.7	445.0
Operating Expense:
Research and Development Expense	30.1	32.7	30.7
Selling and Administrative Expense	314.0	357.2	356.3
Total Operating Expense	344.1	389.9	387.0
Profit from Operations	63.7	71.8	58.0
Other Income (Expense):
Interest Income	3.3	3.3	3.0
Interest Expense	(20.7)	(21.1)	(23.3)
Net Foreign Currency Transaction Losses	(5.3)	(0.7)	(1.1)
Other Income (Expense), Net	0.1	0.7	(0.8)
Total Other Expense, Net	(22.6)	(17.8)	(22.2)
Profit Before Income Taxes	41.1	54.0	35.8
Income Tax Expense	7.4	8.1	2.3
Net Earnings Including Noncontrolling Interest	33.7	45.9	33.5
Net Earnings Attributable to Noncontrolling Interest	0.0	0.1	0.1
Net Earnings Attributable to Tennant Company	$ 33.7	$ 45.8	$ 33.4
Net Earnings Attributable to Tennant Company per Share:
Basic (in dollars per share)	$ 1.84	$ 2.53	$ 1.86
Diluted (in dollars per share)	$ 1.81	$ 2.48	$ 1.82
Weighted Average Shares Outstanding:
Basic (in shares)	18,349,724	18,118,486	17,940,438
Diluted (in shares)	18,635,002	18,453,145	18,338,569