Statements of Consolidated Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash Flows from Operating Activities:
Net cash provided by operating activities	$ 1,541	$ 1,083
Cash Flows from Investing Activities:
Capital expenditures and aircraft purchase deposits paid	(821)	(619)
Increase in short-term and other investments, net	(41)	(96)
Proceeds from sale of property and equipment	17	145
(Increase) decrease in restricted cash, net	12	(5)
Net cash used in investing activities	(833)	(575)
Cash Flows from Financing Activities:
Payments of long-term debt	(1,737)	(696)
Proceeds from issuance of long-term debt	520	86
Principal payments under capital leases	(73)	(64)
Other, net	(45)	6
Net cash used in financing activities	(1,335)	(668)
Net decrease in cash and cash equivalents	(627)	(160)
Cash and cash equivalents at beginning of the period	4,770	6,246
Cash and cash equivalents at end of the period	4,143	6,086
Investing and Financing Activities Not Affecting Cash:
Net property and equipment acquired through the issuance of debt	225	341
Exchanges of certain 6% convertible senior notes for common stock (Note 3)	189
Airport construction financing	29	27
8% Contingent Senior Unsecured Notes, net of discount		48
United Airlines, Inc.
Cash Flows from Operating Activities:
Net cash provided by operating activities	1,538	1,081
Cash Flows from Investing Activities:
Capital expenditures and aircraft purchase deposits paid	(821)	(619)
Increase in short-term and other investments, net	(41)	(96)
Proceeds from sale of property and equipment	16	145
(Increase) decrease in restricted cash, net	12	(5)
Net cash used in investing activities	(834)	(575)
Cash Flows from Financing Activities:
Payments of long-term debt	(1,737)	(696)
Proceeds from issuance of long-term debt	520	86
Principal payments under capital leases	(73)	(64)
Other, net	(42)	8
Net cash used in financing activities	(1,332)	(666)
Net decrease in cash and cash equivalents	(628)	(160)
Cash and cash equivalents at beginning of the period	4,765	6,240
Cash and cash equivalents at end of the period	4,137	6,080
Investing and Financing Activities Not Affecting Cash:
Net property and equipment acquired through the issuance of debt	225	341
Airport construction financing	29	27
8% Contingent Senior Unsecured Notes, net of discount		$ 48