Summary of Significant Accounting Policies - Pre-production Design and Development and Tooling Assets (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
In-process tools and dies built for original equipment customers	$ 143	$ 162

In ProcessTools and Dies Built For Original Equipment Customer

No definition available.

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