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, 2016	Dec. 31, 2015
Pre Production Costs Related to Long Term Supply Arrangements [Line Items]
Recoverable customer E&D and tooling	$ 229.3	$ 215.7
Other current assets
Pre Production Costs Related to Long Term Supply Arrangements [Line Items]
Recoverable customer E&D and tooling	185.9	162.0
Other long-term assets
Pre Production Costs Related to Long Term Supply Arrangements [Line Items]
Recoverable customer E&D and tooling	$ 43.4	$ 53.7