Current Expected Credit Loss (Details) $ in Millions	3 Months Ended
	Mar. 31, 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	4
Write-offs charged against the allowance, Total	(1)
Other, Total	(13)
Balance at March 31, 2020, Total	602
Liabilities for Off Balance Sheet Assets [Roll Forward]
Cumulative effect of accounting change, Off Balance Sheet Assets	12
Current period provision, Off Balance Sheet Assets	(1)
Other, Off Balance Sheet Assets	2
Balance at March 31, 2020, Off Balance Sheet Assets	13
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	4
Write-offs charged against the allowance, Trade and Other	(1)
Other, Trade and Other	(1)
Balance at March 31, 2020, Trade and Other	88
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	1
Other, Trade and Other	(14)
Balance at March 31, 2020, Trade and Other	$ 501