Schedule of Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 4,058	$ 1,884	$ 2,032
Charged to costs and expenses	(937)	2,395	458
Deductions	357	221	606
Balance at end of period	2,764	4,058	1,884
Accounting Standards Update 2016-13 [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Increase (Decrease) Adjustment		(252)
Credit losses [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	1,332	530	592
Charged to costs and expenses	(306)	840	310
Deductions	100	38	372
Balance at end of period	926	1,332	530
Doubtful receivables [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	57	49	94
Charged to costs and expenses	3	28	18
Deductions	13	20	63
Balance at end of period	47	57	49
Inventories (primarily service part obsolescence) [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	688	462	373
Charged to costs and expenses	36	226	89
Deductions	0	0	0
Balance at end of period	724	688	462
Deferred tax assets [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	1,981	843	973
Charged to costs and expenses	(670)	1,301	41
Deductions	244	163	171
Balance at end of period	1,067	1,981	843
Valuation Allowance Of Deferred Tax Assets Recognized In Accumulated Other Comprehensive Income Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Charged to costs and expenses	(127)	77	78
Valuation Allowance of Deferred Tax Assets Recognized in Income Statement [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Charged to costs and expenses	$ (797)	$ 1,200	$ (52)