Long-Term Financing Receivables(Class and Credit Risk Information) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total long-term receivables	$ 550	$ 527
Long-term trade accounts receivable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total long-term receivables	294	269
Notes and leases receivable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total long-term receivables	$ 256	$ 258