Summary of Accounting Policies - Pre-production Design and Development and Tooling Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Unbilled pre-production design and development costs	$ 23	$ 30
Original Equipment tools and dies, owned	59
In-process tools and dies built for original equipment customers	$ 98	$ 86