Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Receivable, allowance	$ 5.3	$ 5.3
Accumulated depreciation	$ 261.5	$ 258.4
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)	18,589,675	18,535,116
Common stock, shares outstanding (in shares)	18,589,675	18,535,116