Additional Financial Information - Income Statement Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation expense	$ 14,119	$ 14,275	$ 14,371
Interest costs on debt balances	5,148	4,632	5,221
Net amortization of debt discount	178	170	165
Capitalized interest costs	(1,841,000)	(555)	(656)
Advertising expense	3,394	3,107	3,071
Other income (expense), net
Interest income	48	65	121
Other components of net periodic benefit (cost) income	3,785	(425)	627
Early debt extinguishment costs	3,541	129	3,604
Other, net	20	(50)	(44)
Other income (expense), net	$ 312	$ (539)	$ (2,900)