Inventories (Tables)

9 Months Ended

Sep. 30, 2017

Inventory Disclosure [Abstract]

Inventories

Inventories are valued at the lower of cost (on a first-in, first-out basis) and net realizable value. Inventory balances were as follows:

($ in millions)	September 30, 2017		December 31, 2016
Raw materials	$	89.2	$	78.0
Work in process	33.7		28.9
Finished goods	92.9		92.4
	$	215.8	$	199.3