Current Expected Credit Loss (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Financing Receivable Allowance For Credit Losses [Roll Forward]
Balance at December 31, 2019, Total	$ 503
Cumulative effect of accounting change, Total	109
Current period provision, Total	10
Write-offs charged against the allowance, Total	(2)
Other, Total	(12)
Balance at June 30, 2020, Total	608
Liabilities for Off-Balance Sheet Assets [Roll Forward]
Cumulative effect of accounting change, Off-Balance Sheet Assets	12
Balance at June 30, 2020, Off-Balance Sheet Assets	12
Trade Accounts Receivable [Member]
Financing Receivable Allowance For Credit Losses [Roll Forward]
Balance at December 31, 2019, Trade and Other	34
Cumulative effect of accounting change, Trade and Other	52
Current period provision, Trade and Other	8
Write-offs charged against the allowance, Trade and Other	(1)
Balance at June 30, 2020, Trade and Other	93
Loans And Finance Receivables [Member]
Financing Receivable Allowance For Credit Losses [Roll Forward]
Balance at December 31, 2019, Trade and Other	469
Cumulative effect of accounting change, Trade and Other	45
Current period provision, Trade and Other	2
Write-offs charged against the allowance, Trade and Other	(1)
Other, Trade and Other	(12)
Balance at June 30, 2020, Trade and Other	$ 503