Note 6 - Inventories - Inventories (Details) - USD ($) $ in Millions		Sep. 30, 2021	Dec. 31, 2020
Excess of FIFO over LIFO cost(a)	[1]	$ (38.3)	$ (31.4)
Total LIFO inventories		50.2	32.6
Total FIFO inventories		108.1	95.1
Total inventories		158.3	127.7
LIFO Inventory [Member]
Finished goods		51.4	42.4
Raw materials, production parts and work-in-process		37.1	21.6
FIFO Inventory [Member]
Finished goods		55.1	55.0
Raw materials, production parts and work-in-process		$ 53.0	$ 40.1

[1] The difference between replacement cost and the stated LIFO inventory value is not materially different from the reserve for the LIFO valuation method.