Supplemental Balance Sheet Data - Inventories (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Inventories by major class:
Raw materials	$ 32.1	$ 31.6
Work in progress	30.7	26.8
Finished goods	59.3	63.0
Supplies and other	3.2	3.1
Inventories, gross	125.3	124.5
Adjust FIFO inventories to LIFO cost	(8.2)	(8.2)
Total	117.1	116.3
FIFO values of inventories valued on the LIFO method	111.5	$ 106.8
Maximum
Inventories by major class:
Decrease in LIFO inventory (less than)	$ 0.1