Debt - Assets and Liabilities Related to Asset-backed Debt Arrangements (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Prepaid expenses and other	$ 7,010	$ 7,973
Other assets	19,678	19,769
Accounts payable and accrued liabilities	19,413	23,374
Debt maturing within one year	22,629	22,633
Long-term debt	121,020	121,381
Variable Interest Entity, Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Accounts receivable, net	17,913	18,339
Prepaid expenses and other	331	322
Other assets	10,997	11,647
Accounts payable and accrued liabilities	37	37
Debt maturing within one year	15,847	17,312
Long-term debt	$ 10,490	$ 8,827