Statements of Consolidated Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating revenue:
Operating revenue	$ 3,221	$ 7,979
Operating expense:
Salaries and related costs	2,224	2,955
Aircraft fuel	851	1,726
Depreciation and amortization	623	615
Landing fees and other rent	519	623
Regional capacity purchase	479	737
Aircraft maintenance materials and outside repairs	269	434
Distribution expenses	85	295
Aircraft rent	55	50
Special charges (credits)	(1,377)	63
Other operating expenses	874	1,453
Total operating expense	4,602	8,951
Operating loss	(1,381)	(972)
Nonoperating income (expense):
Interest expense	(353)	(171)
Interest capitalized	17	21
Interest income	7	26
Unrealized losses on investments, net	(22)	(319)
Miscellaneous, net	(19)	(699)
Total nonoperating expense, net	(370)	(1,142)
Loss before income tax benefit	(1,751)	(2,114)
Income tax benefit	(394)	(410)
Net loss	$ (1,357)	$ (1,704)
Loss per share, basic and diluted (in dollars per share)	$ (4.29)	$ (6.86)
United Airlines, Inc.
Operating revenue:
Operating revenue	$ 3,221	$ 7,979
Operating expense:
Salaries and related costs	2,224	2,955
Aircraft fuel	851	1,726
Depreciation and amortization	623	615
Landing fees and other rent	519	623
Regional capacity purchase	479	737
Aircraft maintenance materials and outside repairs	269	434
Distribution expenses	85	295
Aircraft rent	55	50
Special charges (credits)	(1,377)	63
Other operating expenses	874	1,453
Total operating expense	4,602	8,951
Operating loss	(1,381)	(972)
Nonoperating income (expense):
Interest expense	(353)	(171)
Interest capitalized	17	21
Interest income	7	26
Unrealized losses on investments, net	(22)	(319)
Miscellaneous, net	(19)	(698)
Total nonoperating expense, net	(370)	(1,141)
Loss before income tax benefit	(1,751)	(2,113)
Income tax benefit	(394)	(409)
Net loss	(1,357)	(1,704)
Passenger revenue
Operating revenue:
Operating revenue	2,316	7,065
Passenger revenue | United Airlines, Inc.
Operating revenue:
Operating revenue	2,316	7,065
Cargo
Operating revenue:
Operating revenue	497	264
Cargo | United Airlines, Inc.
Operating revenue:
Operating revenue	497	264
Other operating revenue
Operating revenue:
Operating revenue	408	650
Other operating revenue | United Airlines, Inc.
Operating revenue:
Operating revenue	$ 408	$ 650