Summarized Balance Sheet Information of Reportable Segments (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 35.7	$ 61.9	$ 47.8
Trade accounts receivable, net	77.2
Inventories	101.2
Prepaid expenses, supplies, and other current assets	24.7	1.0
Total current assets	271.8	81.0
Property, plant and equipment, net	301.5	0.1
Intangible assets, net	15.1	0.1
Goodwill	104.3
Other noncurrent assets	8.2	1.1
TOTAL ASSETS	700.9	121.7
Current liabilities:
Trade payables	100.9
Accrued liabilities	51.8	7.1
Total current liabilities	155.1	15.2
Accrued pension benefits	38.0
Environmental liabilities	11.7
Other noncurrent liabilities	5.4	0.1
TOTAL LIABILITIES	536.6	$ 36.1
RANA
Current assets:
Cash and cash equivalents	8.1
Trade accounts receivable, net	63.7
Inventories	61.7
Prepaid expenses, supplies, and other current assets	12.5
Total current assets	146.0
Property, plant and equipment, net	199.3
Intangible assets, net	15.0
Goodwill	95.4
Other noncurrent assets	4.9
TOTAL ASSETS	460.6
Current liabilities:
Trade payables	58.1
Accrued liabilities	34.3
Total current liabilities	92.4
Environmental liabilities	11.7
Other noncurrent liabilities	4.1
TOTAL LIABILITIES	108.2
RAEU
Current assets:
Cash and cash equivalents	7.2
Trade accounts receivable, net	13.5
Financing receivable	32.7
Inventories	38.5
Prepaid expenses, supplies, and other current assets	6.8
Total current assets	98.7
Property, plant and equipment, net	102.2
Goodwill	8.9
Other noncurrent assets	1.9
TOTAL ASSETS	211.7
Current liabilities:
Trade payables	42.3
Accrued liabilities	14.6
Total current liabilities	56.9
Accrued pension benefits	38.0
Other noncurrent liabilities	1.4
TOTAL LIABILITIES	$ 96.3