Components of Accounts and Other Receivables (Detail) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Current
Trade accounts receivable	$ 554.1	$ 456.5
Trade notes receivable	0.5	1.5
Total trade receivables	554.6	458.0
Other notes receivable:
Other notes receivable	0.0	0.0
Income tax receivables	4.6	9.1
Other receivables	26.0	26.7
Subtotal other receivables	30.6	35.8
Total trade and other receivables	585.2	493.8
Allowance for doubtful accounts:
Trade accounts receivable	(7.3)	(7.1)
Trade notes receivable	(0.2)	(0.1)
Total trade receivables	(7.5)	(7.2)
Other notes receivable	0.0	0.0
Total allowance for doubtful accounts	(7.5)	(7.2)
Total net receivables	577.7	486.6
Long-term
Trade accounts receivable	0.0	0.0
Trade notes receivable	0.5	0.7
Total trade receivables	0.5	0.7
Other notes receivable:
Other notes receivable	24.6	24.6
Income tax receivables	0.0	0.0
Other receivables	0.0	0.0
Subtotal other receivables	24.6	24.6
Total trade and other receivables	25.1	25.3
Allowance for doubtful accounts:
Trade accounts receivable	0.0	0.0
Trade notes receivable	(0.1)	(0.2)
Total trade receivables	(0.1)	(0.2)
Other notes receivable	0.0	0.0
Total allowance for doubtful accounts	(0.1)	(0.2)
Total net receivables	$ 25.0	$ 25.1