Statements of Consolidated Operations (UA) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating revenue:
Total operating revenue	$ 53,717	$ 44,955	$ 24,634
Operating expense:
Salaries and related costs	14,787	11,466	9,566
Aircraft fuel	12,651	13,113	5,755
Landing fees and other rent	3,076	2,576	2,416
Aircraft maintenance materials and outside repairs	2,736	2,153	1,316
Depreciation and amortization	2,671	2,456	2,485
Regional capacity purchase	2,400	2,299	2,147
Distribution expenses	1,977	1,535	677
Aircraft rent	197	252	228
Special charges	949	140	(3,367)
Other operating expenses	8,062	6,628	4,433
Total operating expense	49,506	42,618	25,656
Operating income (loss)	4,211	2,337	(1,022)
Nonoperating income (expense):
Interest expense	(1,956)	(1,778)	(1,657)
Interest income	827	298	36
Interest capitalized	182	105	80
Unrealized gains (losses) on investments, net	27	20	(34)
Miscellaneous, net	96	8	40
Total nonoperating expense, net	(824)	(1,347)	(1,535)
Income (loss) before income taxes	3,387	990	(2,557)
Income tax expense (benefit)	769	253	(593)
Net income (loss)	2,618	737	(1,964)
United Airlines, Inc.
Operating revenue:
Total operating revenue	53,717	44,955	24,634
Operating expense:
Salaries and related costs	14,787	11,466	9,566
Aircraft fuel	12,651	13,113	5,755
Landing fees and other rent	3,076	2,576	2,416
Aircraft maintenance materials and outside repairs	2,736	2,153	1,316
Depreciation and amortization	2,671	2,456	2,485
Regional capacity purchase	2,400	2,299	2,147
Distribution expenses	1,977	1,535	677
Aircraft rent	197	252	228
Special charges	949	140	(3,367)
Other operating expenses	8,059	6,626	4,431
Total operating expense	49,503	42,616	25,654
Operating income (loss)	4,214	2,339	(1,020)
Nonoperating income (expense):
Interest expense	(1,956)	(1,778)	(1,657)
Interest income	827	298	36
Interest capitalized	182	105	80
Unrealized gains (losses) on investments, net	27	20	(34)
Miscellaneous, net	96	8	40
Total nonoperating expense, net	(824)	(1,347)	(1,535)
Income (loss) before income taxes	3,390	992	(2,555)
Income tax expense (benefit)	770	253	(593)
Net income (loss)	2,620	739	(1,962)
Passenger revenue
Operating revenue:
Total operating revenue	49,046	40,032	20,197
Passenger revenue | United Airlines, Inc.
Operating revenue:
Total operating revenue	49,046	40,032	20,197
Cargo
Operating revenue:
Total operating revenue	1,495	2,171	2,349
Cargo | United Airlines, Inc.
Operating revenue:
Total operating revenue	1,495	2,171	2,349
Other operating revenue
Operating revenue:
Total operating revenue	3,176	2,752	2,088
Other operating revenue | United Airlines, Inc.
Operating revenue:
Total operating revenue	$ 3,176	$ 2,752	$ 2,088