Debt - Schedule of Assets and Liabilities Related to Asset-backed Debt Arrangements (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Accounts receivable, net	$ 23,846	$ 23,917
Prepaid expenses and other	6,906	6,710
Other assets	13,329	10,879
Accounts payable and accrued liabilities	24,833	20,658
Debt maturing within one year	7,443	5,889
Long-term debt	143,425	123,173
Variable Interest Entity, Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Accounts receivable, net	10,705	9,257
Prepaid expenses and other	1,094	1,128
Other assets	5,455	2,950
Accounts payable and accrued liabilities	10	8
Debt maturing within one year	5,024	4,191
Long-term debt	$ 9,178	$ 6,413