Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Amortized intangible assets:
Other intangible assets, gross	$ 1,764	$ 1,266
Other intangible assets, accumulated amortization	455	397
Other intangible assets, net	1,309	869
Patents, Trademarks, and Trade Names [Member]
Amortized intangible assets:
Other intangible assets, gross	465	382
Other intangible assets, accumulated amortization	198	188
Other intangible assets, net	267	194
Customer Lists and Other [Member]
Amortized intangible assets:
Other intangible assets, gross	1,299	884
Other intangible assets, accumulated amortization	257	209
Other intangible assets, net	$ 1,042	$ 675