Defined Benefit Plans - Accumulated Benefit Obligation (Detail) - Accounting Standards Update 2017-07 [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Decrease to operating income	$ (9.6)	$ (14.1)
Cost of products sold [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease to operating income	7.5	8.5
Selling, general and administrative expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease to operating income	$ 2.1	$ 5.6

Amount of the effect of a change in accounting principle on operating profit or loss.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22580-107794

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