Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Receivable, allowance	$ 5.3	$ 4.6
Accumulated depreciation	$ 258.4	$ 252.0
Common stock, par value (in dollars per share)	$ 0.375	$ 0.375
Common stock, shares authorized (in shares)	60,000,000	60,000,000
Common stock, shares issued (in shares)	15,535,116	18,503,805
Common stock, shares outstanding (in shares)	15,535,116	18,503,805