Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Income Statement (Detail) - Kronos - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule Of Equity Method Investments [Line Items]
Net sales	$ 471.8	$ 441.4	$ 902.2	$ 811.2
Cost of sales	300.0	309.0	555.6	572.8
Income from operations	119.9	74.3	227.4	130.7
Income tax expense (benefit)	32.4	(131.1)	61.4	(120.1)
Net income	$ 77.7	$ 196.5	$ 148.4	$ 233.3

Equity method investment summarized financial information income tax expense benefit.

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The amount of the cost of sales reported by an equity method investment of the entity.

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The amount of gross profit (loss) reported by an equity method investment of the entity.

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The amount of net income (loss) reported by an equity method investment of the entity.

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The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity.

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