Inventories (Tables)

9 Months Ended

Sep. 30, 2018

Inventory Disclosure [Abstract]

Schedule of Inventories

Inventories at September 30, 2018 and December 31, 2017 were as follows (in millions):

	September 30, 2018			December 31, 2017
Raw materials and supplies	$	204.3		$	162.8
Work-in-process	929.9			955.5
Finished goods	190.0			165.0
Total inventories at current cost	1,324.2			1,283.3
Adjustment from current cost to LIFO cost basis	1.7			43.1
Inventory valuation reserves	(86.1		)	(121.5		)
Progress payments	—			(28.8		)
Total inventories, net	$	1,239.8		$	1,176.1

Schedule of Inventory Valuation Impact on Income

Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV inventory reserves were as follows (in millions):

	Nine months ended September 30,
	2018			2017
LIFO benefit (charge)	$	(29.5	)	$	(51.5	)
NRV benefit (charge)	29.5			51.3
Net cost of sales impact	$	—		$	(0.2	)