Condensed Statements of Consolidated Cash Flows (Unaudited) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Cash Flows from Operating Activities:
Net cash provided by operating activities		$ 447	$ 63
Cash Flows from Investing Activities:
Capital expenditures		(444)	(1,959)
Purchases of short-term and other investments		0	(541)
Proceeds from sale of short-term and other investments		105	927
Other, net		10	1
Net cash used in investing activities		(329)	(1,572)
Cash Flows from Financing Activities:
Proceeds from issuance of debt, net of discounts and fees		1,336	2,813
Proceeds from equity issuance		532	0
Payments of long-term debt, finance leases and other financing liabilities		(569)	(253)
Repurchases of common stock		0	(353)
Other, net		(21)	(18)
Net cash provided by financing activities		1,278	2,189
Net increase in cash, cash equivalents and restricted cash		1,396	680
Cash, cash equivalents and restricted cash at beginning of the period		11,742	2,868
Cash, cash equivalents and restricted cash at end of the period	[1]	13,138	3,548
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt, finance leases and other		509	128
Lease modifications and lease conversions		22	439
Right-of-use assets acquired through operating leases		180	30
Warrants received for entering into agreements with Archer Aviation Inc ("Archer")		81	0
United Airlines, Inc.
Cash Flows from Operating Activities:
Net cash provided by operating activities		426	45
Cash Flows from Investing Activities:
Capital expenditures		(444)	(1,959)
Purchases of short-term and other investments		0	(541)
Proceeds from sale of short-term and other investments		105	927
Other, net		10	1
Net cash used in investing activities		(329)	(1,572)
Cash Flows from Financing Activities:
Proceeds from issuance of debt, net of discounts and fees		1,336	2,813
Proceeds from equity issuance		532	0
Payments of long-term debt, finance leases and other financing liabilities		(569)	(253)
Dividend to UAL		0	(353)
Net cash provided by financing activities		1,299	2,207
Net increase in cash, cash equivalents and restricted cash		1,396	680
Cash, cash equivalents and restricted cash at beginning of the period		11,742	2,862
Cash, cash equivalents and restricted cash at end of the period	[2]	13,138	3,542
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt, finance leases and other		509	128
Lease modifications and lease conversions		22	439
Right-of-use assets acquired through operating leases		180	30
Warrants received for entering into agreements with Archer Aviation Inc ("Archer")		$ 81	$ 0

[1] The following table provides a reconciliation of cash, cash equivalents and restricted cash to amounts reported within the consolidated balance sheet: Current assets:Cash and cash equivalents$12,666 $3,442 Restricted cash — Current254 — Restricted cash — Non-Current218 106 Total cash, cash equivalents and restricted cash $13,138 $3,548 

[2] The following table provides a reconciliation of cash, cash equivalents and restricted cash to amounts reported within the consolidated balance sheet: Current assets:Cash and cash equivalents$12,666 $3,436 Restricted cash — Current254 — Restricted cash — Non-Current218 106 Total cash, cash equivalents and restricted cash$13,138 $3,542