Customer Financing (Financing Receivable Credit Quality Indicators) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 69
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	92
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	17
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	304
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	180
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	736
Carrying value of financing receivables	1,398	$ 1,472
BBB Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	400
Carrying value of financing receivables	400
BB Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	69
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	54
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	17
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	152
Carrying value of financing receivables	292
B Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	53
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	171
Carrying value of financing receivables	224
CCC Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	38
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	251
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	180
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	13
Carrying value of financing receivables	$ 482