Summary of Significant Accounting Policies - Classification of Recoverable Customer Engineering, Development and Tooling Costs related to Long-Term Supply Agreements (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pre Production Costs Related to Long Term Supply Arrangements [Line Items]
Recoverable customer E&D and tooling	$ 241.3	$ 307.4
Current
Pre Production Costs Related to Long Term Supply Arrangements [Line Items]
Recoverable customer E&D and tooling	160.9	248.1
Long-term
Pre Production Costs Related to Long Term Supply Arrangements [Line Items]
Recoverable customer E&D and tooling	$ 80.4	$ 59.3

The carrying amount as of the balance sheet date of capitalized preproduction costs incurred on long-term supply arrangements, including recoverable costs to design and develop products.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 10
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6387057&loc=d3e6169-108318

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 10
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6387057&loc=d3e6233-108318

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 10
-Section S99
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=27011391&loc=d3e105117-122735

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