Customer Financing (Financing Receivable Credit Quality Indicators) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total financing receivables	$ 1,472	$ 1,855
BBB Credit Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total financing receivables	573	883
BB Credit Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total financing receivables	385	430
B Credit Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total financing receivables	122	135
CCC Credit Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total financing receivables	$ 392	$ 407