Accounting Policies and Supplemental Disclosures - Accounts Receivable, Net and Other (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net and other	$ 32,504	$ 32,891
Allowance for doubtful accounts	1,100	1,100
Customer receivables, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net and other	20,900	20,200
Vendor receivables, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net and other	4,200	5,300
Seller receivables, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net and other	$ 1,100	$ 1,000