CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Allowance for credit loss	$ 8.0	$ 6.1
Accumulated depreciation	$ 297.4	$ 279.3
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)	18,540,598	18,540,598
Common stock, shares outstanding (in shares)	18,521,485	18,521,485