Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Amortized intangible assets:
Other intangible assets, gross	$ 1,266	$ 1,266
Other intangible assets, accumulated amortization	415	397
Other intangible assets, net	851	869
Patents, Trademarks, and Trade Names [Member]
Amortized intangible assets:
Other intangible assets, gross	380	382
Other intangible assets, accumulated amortization	191	188
Other intangible assets, net	189	194
Customer Lists and Other [Member]
Amortized intangible assets:
Other intangible assets, gross	886	884
Other intangible assets, accumulated amortization	224	209
Other intangible assets, net	$ 662	$ 675