United Airlines (UAL) 10-K 20 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 14, 2014	Jun. 30, 2013
Document Information [Line Items]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'UAL	'	'
Entity Registrant Name	'United Continental Holdings, Inc.	'	'
Entity Central Index Key	'0000100517	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	371,556,314	'
Entity Public Float	'	'	$11,107,386,154
United Airlines, Inc.	'	'	'
Document Information [Line Items]	'	'	'
Entity Registrant Name	'United Airlines, Inc.	'	'
Entity Central Index Key	'0000319687	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	1,000	'

Statements_of_Consolidated_Ope

Statements of Consolidated Operations (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating revenue:	'	'	'
Passenger-Mainline	$25,997	$25,804	$25,975
Passenger-Regional	7,125	6,779	6,536
Total passenger revenue	33,122	32,583	32,511
Cargo	882	1,018	1,167
Special revenue item	'	'	107
Other operating revenue	4,275	3,551	3,325
Total revenue	38,279	37,152	37,110
Operating expense:	'	'	'
Aircraft fuel	12,345	13,138	12,375
Salaries and related costs	8,625	7,945	7,652
Regional capacity purchase	2,419	2,470	2,403
Landing fees and other rent	2,090	1,929	1,928
Aircraft maintenance materials and outside repairs	1,821	1,760	1,744
Depreciation and amortization	1,689	1,522	1,547
Distribution expenses	1,390	1,352	1,435
Aircraft rent	936	993	1,009
Special charges	520	1,323	592
Other operating expenses	5,195	4,681	4,603
Total operating expenses	37,030	37,113	35,288
Operating income	1,249	39	1,822
Nonoperating income (expense):	'	'	'
Interest expense	-783	-835	-949
Interest capitalized	49	37	32
Interest income	21	23	20
Miscellaneous, net	3	12	-80
Total other income (expense)	-710	-763	-977
Income (loss) before income taxes	539	-724	845
Income tax expense (benefit)	-32	-1	5
Net income (loss)	571	-723	840
Earnings (loss) per share, basic	$1.64	($2.18)	$2.54
Earnings (loss) per share, diluted	$1.53	($2.18)	$2.26
United Airlines, Inc.	'	'	'
Operating revenue:	'	'	'
Passenger-Mainline	25,997	25,804	25,975
Passenger-Regional	7,125	6,779	6,536
Total passenger revenue	33,122	32,583	32,511
Cargo	882	1,018	1,167
Special revenue item	'	'	107
Other operating revenue	4,283	3,559	3,334
Total revenue	38,287	37,160	37,119
Operating expense:	'	'	'
Aircraft fuel	12,345	13,138	12,375
Salaries and related costs	8,625	7,945	7,652
Regional capacity purchase	2,419	2,470	2,403
Landing fees and other rent	2,090	1,929	1,928
Aircraft maintenance materials and outside repairs	1,821	1,760	1,744
Depreciation and amortization	1,689	1,522	1,547
Distribution expenses	1,390	1,352	1,435
Aircraft rent	936	993	1,009
Special charges	520	1,323	592
Other operating expenses	5,193	4,677	4,597
Total operating expenses	37,028	37,109	35,282
Operating income	1,259	51	1,837
Nonoperating income (expense):	'	'	'
Interest expense	-781	-823	-937
Interest capitalized	49	37	32
Interest income	21	23	20
Miscellaneous, net	89	55	-104
Total other income (expense)	-622	-708	-989
Income (loss) before income taxes	637	-657	848
Income tax expense (benefit)	-17	4	-2
Net income (loss)	$654	($661)	$850

Statements_of_Consolidated_Com

Statements of Consolidated Comprehensive Income (Loss) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Net income (loss)	$571		($723)		$840
Other comprehensive income (loss), net change related to:	'		'		'
Fuel derivative financial instruments	21		90		-340
Employee benefit plans	1,626		-730		-464
Investments and other	7		11		'
Comprehensive income (loss) adjustments	1,654	[1]	-629	[1]	-804	[1]
Total comprehensive income (loss), net	2,225		-1,352		36
United Airlines, Inc.	'		'		'
Net income (loss)	654		-661		850
Other comprehensive income (loss), net change related to:	'		'		'
Fuel derivative financial instruments	21		90		-340
Employee benefit plans	1,626		-730		-464
Investments and other	8		12		-2
Other	6		'		'
Comprehensive income (loss) adjustments	1,661		-628		-806
Total comprehensive income (loss), net	$2,315		($1,289)		$44
[1]	UAL and United amounts are substantially the same except for an additional $6 million of income tax benefit at United in 2013. In addition, United had additional (losses) gains related to investments and other of $(2) million, $1 million and $1 million in 2011, 2012 and 2013, respectively.

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Current assets:	'		'
Cash and cash equivalents	$3,220		$4,770
Short-term investments	1,901		1,773
Total unrestricted cash, cash equivalents and short-term investments	5,121		6,543
Restricted cash	31		65
Receivables, less allowance for doubtful accounts	1,503		1,338
Aircraft fuel, spare parts and supplies, less obsolescence allowance	667		695
Deferred income taxes	676		543
Prepaid expenses and other	704		865
Total current assets	8,702		10,049
Operating property and equipment: Owned-	'		'
Flight equipment	18,786		17,561
Other property and equipment	3,687		3,269
Operating property and equipment - owned, gross	22,473		20,830
Less-Accumulated depreciation and amortization	-6,080		-5,006
Operating property and equipment - owned, net	16,393		15,824
Purchase deposits for flight equipment	706		462
Capital leases-	'		'
Flight equipment	1,490		1,484
Other property and equipment	307		235
Operating property and equipment - capital leases, gross	1,797		1,719
Less-Accumulated amortization	-849		-713
Operating property and equipment - capital leases, net	948		1,006
Total property, plant, and equipment, net	18,047		17,292
Other assets:	'		'
Goodwill	4,523		4,523
Intangibles, less accumulated amortization	4,436		4,597
Restricted cash	364		382
Other, net	740		785
Other assets total	10,063		10,287
Total assets	36,812		37,628
Current liabilities:	'		'
Advance ticket sales	3,405		3,360
Frequent flyer deferred revenue	2,369		2,364
Accounts payable	2,087		2,312
Accrued salaries and benefits	1,696		1,763
Current maturities of long-term debt	1,368		1,812
Current maturities of capital leases	117	[1]	122
Other	1,065		1,085
Total current liabilities	12,107		12,818
Long-term debt	10,171		10,440
Long-term obligations under capital leases	753	[1]	792
Other liabilities and deferred credits:	'		'
Frequent flyer deferred revenue	2,535		2,756
Postretirement benefit liability	1,703		2,614
Pension liability	1,650		2,400
Advanced purchase of miles	1,338		1,537
Deferred income taxes	1,662		1,543
Lease fair value adjustment, net	626		881
Other	1,283		1,366
Total non-current liabilities	10,797		13,097
Commitments and contingencies	'		'
Stockholder's equity:	'		'
Preferred stock	'		'
Common stock	4		3
Additional capital invested	7,425		7,145
Accumulated deficit	-5,015		-5,586
Stock held in treasury, at cost	-38		-35
Accumulated other comprehensive income (loss)	608	[2]	-1,046	[2]
Total stockholders' equity	2,984		481
Total liabilities and stockholders' equity (deficit)	36,812		37,628
United Airlines, Inc.	'		'
Current assets:	'		'
Cash and cash equivalents	3,214		4,765
Short-term investments	1,901		1,773
Total unrestricted cash, cash equivalents and short-term investments	5,115		6,538
Restricted cash	31		65
Receivables, less allowance for doubtful accounts	1,503		1,338
Aircraft fuel, spare parts and supplies, less obsolescence allowance	667		695
Deferred income taxes	674		546
Receivables from related parties	'		226
Prepaid expenses and other	705		841
Total current assets	8,695		10,249
Operating property and equipment: Owned-	'		'
Flight equipment	18,786		17,561
Other property and equipment	3,687		3,269
Operating property and equipment - owned, gross	22,473		20,830
Less-Accumulated depreciation and amortization	-6,080		-5,006
Operating property and equipment - owned, net	16,393		15,824
Purchase deposits for flight equipment	706		462
Capital leases-	'		'
Flight equipment	1,490		1,484
Other property and equipment	307		235
Operating property and equipment - capital leases, gross	1,797		1,719
Less-Accumulated amortization	-849		-713
Operating property and equipment - capital leases, net	948		1,006
Total property, plant, and equipment, net	18,047		17,292
Other assets:	'		'
Goodwill	4,523		4,523
Intangibles, less accumulated amortization	4,436		4,597
Restricted cash	364		382
Other, net	1,221		1,052
Other assets total	10,544		10,554
Total assets	37,286		38,095
Current liabilities:	'		'
Advance ticket sales	3,405		3,360
Frequent flyer deferred revenue	2,369		2,364
Accounts payable	2,092		2,316
Accrued salaries and benefits	1,696		1,763
Current maturities of long-term debt	1,368		1,812
Current maturities of capital leases	117		122
Payables to related parties	114		75
Other	1,064		1,140
Total current liabilities	12,225		12,952
Long-term debt	10,020		10,038
Long-term obligations under capital leases	753		792
Other liabilities and deferred credits:	'		'
Frequent flyer deferred revenue	2,535		2,756
Postretirement benefit liability	1,703		2,614
Pension liability	1,650		2,400
Advanced purchase of miles	1,338		1,537
Deferred income taxes	1,661		1,470
Lease fair value adjustment, net	626		881
Other	1,552		1,494
Total non-current liabilities	11,065		13,152
Commitments and contingencies	'		'
Stockholder's equity:	'		'
Additional capital invested	7,590		7,611
Accumulated deficit	-4,743		-5,397
Accumulated other comprehensive income (loss)	608		-1,053
Receivable from related parties	-232		'
Total stockholders' equity	3,223		1,161
Total liabilities and stockholders' equity (deficit)	$37,286		$38,095
[1]	As of December 31, 2013, United's aircraft capital lease minimum payments relate to leases of 47 mainline and 38 regional aircraft as well as to leases of nonaircraft assets. Imputed interest rate ranges are 4.8% to 18.5%.
[2]	UAL and United amounts are substantially the same except for an additional $6 million of income tax benefit at United in 2013. In addition, United had additional (losses) gains related to investments and other of $(2) million, $1 million and $1 million in 2011, 2012 and 2013, respectively.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Receivables, allowance for doubtful accounts	$13	$13
Aircraft fuel, spare parts and supplies, obsolescence allowance	162	125
Intangibles, accumulated amortization	933	792
Common stock, par value	$0.01	$0.01
Common shares, authorized	1,000,000,000	1,000,000,000
Common shares, outstanding	362,283,555	332,472,779
United Airlines, Inc.	'	'
Receivables, allowance for doubtful accounts	13	13
Aircraft fuel, spare parts and supplies, obsolescence allowance	162	125
Intangibles, accumulated amortization	$933	$792
Common stock, par value	$0.01	$0.01
Common shares, authorized	1,000	1,000
Common shares, issued	1,000	1,000
Common shares, outstanding	1,000	1,000

Statements_of_Consolidated_Cas

Statements of Consolidated Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities:	'	'	'
Net income (loss)	$571	($723)	$840
Adjustments to reconcile net income (loss) to net cash provided (used) by operating activities -	'	'	'
Depreciation and amortization	1,689	1,522	1,547
Debt discount and lease fair value amortization	-188	-247	-186
Amortization of capitalized financing costs	73	52	52
Pension and postretirement amortization	42	18	-23
Special charges, non-cash portion	50	389	46
Deferred income taxes	-14	13	-6
Share-based compensation	11	14	17
Other operating activities	80	48	25
Changes in operating assets and liabilities -	'	'	'
Decrease in frequent flyer deferred revenue and advanced purchase of miles	-415	-712	-110
Increase (decrease) in accounts payable	-265	285	177
(Increase) decrease in other assets	164	-484	-181
Increase (decrease) in other liabilities	-201	415	243
Increase in receivables	-142	-21	-87
Unrealized (gain) loss on fuel derivatives and change in related pending settlements	-56	120	-2
Increase in advance ticket sales	45	246	115
Increase in fuel hedge collateral	'	'	-59
Net cash provided by operating activities	1,444	935	2,408
Cash Flows from Investing Activities:	'	'	'
Capital expenditures	-2,164	-2,016	-840
Proceeds from sale of property and equipment	152	183	123
Increase in short-term and other investments, net	-120	-245	-898
(Increase) decrease in restricted cash, net	52	122	-185
Other, net	58	-1	1
Net cash used in investing activities	-2,022	-1,957	-1,799
Cash Flows from Financing Activities:	'	'	'
Payments of long-term debt	-2,185	-1,392	-2,367
Proceeds from issuance of long-term debt	1,423	1,121	152
Principal payments under capital leases	-134	-125	-250
Capitalized financing costs	-103	-71	-8
Proceeds from exercise of stock options	29	17	26
Purchases of treasury stock	-3	-4	'
Other	1	'	15
Net cash used in financing activities	-972	-454	-2,432
Net decrease in cash and cash equivalents	-1,550	-1,476	-1,823
Cash and cash equivalents at beginning of year	4,770	6,246	8,069
Cash and cash equivalents at end of year	3,220	4,770	6,246
United Airlines, Inc.	'	'	'
Cash Flows from Operating Activities:	'	'	'
Net income (loss)	654	-661	850
Adjustments to reconcile net income (loss) to net cash provided (used) by operating activities -	'	'	'
Depreciation and amortization	1,689	1,522	1,547
Debt discount and lease fair value amortization	-178	-239	-186
Amortization of capitalized financing costs	73	52	52
Pension and postretirement amortization	42	18	-23
Special charges, non-cash portion	50	389	46
Deferred income taxes	1	13	-5
Share-based compensation	11	14	18
Other operating activities	11	4	48
Changes in operating assets and liabilities -	'	'	'
Decrease in frequent flyer deferred revenue and advanced purchase of miles	-415	-712	-110
Increase (decrease) in accounts payable	-265	285	177
(Increase) decrease in other assets	163	-484	-200
Increase (decrease) in other liabilities	-203	422	263
Increase in receivables	-142	-21	-87
Unrealized (gain) loss on fuel derivatives and change in related pending settlements	-56	120	-2
Increase in advance ticket sales	45	246	115
Increase in fuel hedge collateral	'	'	-59
Increase in intercompany receivables	-5	-9	-83
Increase (decrease) in intercompany payables	-34	-28	46
Net cash provided by operating activities	1,441	931	2,407
Cash Flows from Investing Activities:	'	'	'
Capital expenditures	-2,164	-2,016	-840
Proceeds from sale of property and equipment	152	183	123
Increase in short-term and other investments, net	-120	-240	-898
(Increase) decrease in restricted cash, net	52	121	-185
Other, net	57	'	2
Net cash used in investing activities	-2,023	-1,952	-1,798
Cash Flows from Financing Activities:	'	'	'
Payments of long-term debt	-2,185	-1,392	-2,367
Proceeds from issuance of long-term debt	1,423	1,121	152
Principal payments under capital leases	-134	-125	-250
Capitalized financing costs	-103	-71	-8
Proceeds from exercise of stock options	29	17	26
Other	1	-4	15
Net cash used in financing activities	-969	-454	-2,432
Net decrease in cash and cash equivalents	-1,551	-1,475	-1,823
Cash and cash equivalents at beginning of year	4,765	6,240	8,063
Cash and cash equivalents at end of year	$3,214	$4,765	$6,240

Statements_of_Consolidated_Sto

Statements of Consolidated Stockholder's Equity (USD $)

Total

United Airlines, Inc.

Common Stock

Additional Capital Invested

Additional Capital Invested

Treasury Stock

Accumulated Deficit

Accumulated Deficit

Accumulated Other Comprehensive Income (Loss)

Accumulated Other Comprehensive Income (Loss)

Receivable from parent

In Millions, except Share data

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

Beginning Balance at Dec. 31, 2010

$1,727

$2,331

$3

$7,071

$7,536

($31)

($5,703)

($5,586)

$387

$381

'

Beginning Balance (in shares) at Dec. 31, 2010

'

'

328,000,000

'

'

'

'

'

'

'

'

Net income (loss)

840

850

'

'

'

'

840

850

'

'

'

Other comprehensive income (loss)

-804

[1]

-806

'

'

'

'

'

'

-804

-806

'

Share-based compensation

17

18

'

17

18

'

'

'

'

'

'

Proceeds from exercise of stock options (in shares)

2,000,000

'

3,000,000

'

'

'

'

'

'

'

'

Proceeds from exercise of stock options

26

'

'

26

'

'

'

'

'

'

'

UAL contribution related to stock plans

'

26

'

'

26

'

'

'

'

'

'

Ending Balance at Dec. 31, 2011

1,806

2,419

3

7,114

7,580

-31

-4,863

-4,736

-417

-425

'

Ending Balance (in shares) at Dec. 31, 2011

'

'

331,000,000

'

'

'

'

'

'

'

'

Net income (loss)

-723

-661

'

'

'

'

-723

-661

'

'

'

Other comprehensive income (loss)

-629

[1]

-628

'

'

'

'

'

'

-629

-628

'

Share-based compensation

14

14

'

14

14

'

'

'

'

'

'

Proceeds from exercise of stock options (in shares)

1,000,000

'

1,000,000

'

'

'

'

'

'

'

'

Proceeds from exercise of stock options

17

'

'

17

'

'

'

'

'

'

'

UAL contribution related to stock plans

'

17

'

'

17

'

'

'

'

'

'

Treasury stock acquisitions

-4

'

'

'

'

-4

'

'

'

'

'

Ending Balance at Dec. 31, 2012

481

1,161

3

7,145

7,611

-35

-5,586

-5,397

-1,046

-1,053

'

Ending Balance (in shares) at Dec. 31, 2012

'

'

332,000,000

'

'

'

'

'

'

'

'

Net income (loss)

571

654

'

'

'

'

571

654

'

'

'

Other comprehensive income (loss)

1,654

[1]

1,661

'

'

'

'

'

'

1,654

1,661

'

Shares issued in exchange for redemption of convertible debt (in shares)

'

'

28,000,000

'

'

'

'

'

'

'

'

Shares issued in exchange for redemption of convertible debt

241

'

1

240

'

'

'

'

'

'

'

Income taxes

'

-68

'

'

-68

'

'

'

'

'

'

Contribution of asset by UAL

'

7

'

'

7

'

'

'

'

'

'

Share-based compensation

11

11

'

11

11

'

'

'

'

'

'

Proceeds from exercise of stock options (in shares)

2,000,000

'

2,000,000

'

'

'

'

'

'

'

'

Proceeds from exercise of stock options

29

'

'

29

'

'

'

'

'

'

'

UAL contribution related to stock plans

'

29

'

'

29

'

'

'

'

'

'

Reclassification of related party receivables to equity

'

-232

'

'

'

'

'

'

'

'

-232

Treasury stock acquisitions

-3

'

'

'

'

-3

'

'

'

'

'

Ending Balance at Dec. 31, 2013

$2,984

$3,223

$4

$7,425

$7,590

($38)

($5,015)

($4,743)

$608

$608

($232)

Ending Balance (in shares) at Dec. 31, 2013

'

'

362,000,000

'

'

'

'

'

'

'

'

[1]

UAL and United amounts are substantially the same except for an additional $6 million of income tax benefit at United in 2013. In addition, United had additional (losses) gains related to investments and other of $(2) million, $1 million and $1 million in 2011, 2012 and 2013, respectively.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Significant Accounting Policies	'
	NOTE 1 - SIGNIFICANT ACCOUNTING POLICIES
	(a)	Use of Estimates and Reclassifications—The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. Actual results could differ from those estimates.
	Certain prior year cash flows from operating activities have been reclassified to conform to the current year presentation.
	(b)	Passenger Revenue Recognition—The value of unused passenger tickets is included in current liabilities as advance ticket sales. The Company records passenger ticket sales and tickets sold by other airlines for use on United as passenger revenue when the transportation is provided or upon estimated breakage. Tickets sold by other airlines are recorded at the estimated values to be billed to the other airlines. Differences between amounts billed and the actual amounts may be rejected and rebilled or written off if the amount recorded was different from the original estimate. When necessary, the Company records a reserve against our interline billings and payables if historical experience indicates that these amounts are different. Non-refundable tickets generally expire on the date of the intended flight, unless the date is extended by notification from the customer on or before the intended flight date.
	Fees charged in association with changes or extensions to non-refundable tickets are recorded as other revenue at the time the fee is incurred. The fare on the changed ticket, including any additional collection, is deferred and recognized in accordance with our transportation revenue recognition policy at the time the transportation is provided. Change fees related to non-refundable tickets are considered a separate transaction from the air transportation because they represent a charge for the Company’s additional service to modify a previous sale. Therefore, the pricing of the change fee and the initial customer order are separately determined and represent distinct earnings processes. Refundable tickets expire after one year.
	The Company records an estimate of breakage revenue on the flight date for tickets that will expire unused. These estimates are based on the evaluation of actual historical results and forecasted trends.
	The Company recognizes cargo and other revenue as service is provided.
	Under our capacity purchase agreements (“CPAs”) with regional carriers, we purchase all of the capacity related to aircraft covered by the contracts and are responsible for selling all of the related seat inventory. We record the passenger revenue and related expenses as separate operating revenue and expense in the consolidated statement of operations.
	Accounts receivable primarily consist of amounts due from credit card companies and customers of our aircraft maintenance and cargo transportation services. We provide an allowance for uncollectible accounts equal to the estimated losses expected to be incurred based on historical write-offs and other specific analyses. Bad debt expense and write-offs were not material for the years ended December 31, 2013, 2012 and 2011.
	(c)	Frequent Flyer Accounting—United has a frequent flyer program that is designed to increase customer loyalty. Program participants earn mileage credits (“miles”) by flying on United and certain other participating airlines. Program participants can also earn miles through purchases from other non-airline partners that participate in United’s loyalty program. We sell miles to these partners, which include credit card issuers, retail merchants, hotels, car rental companies and our participating airline partners. Miles can be redeemed for free (other than taxes and government imposed fees), discounted or upgraded air travel and non-travel awards. The Company records its obligation for future award redemptions using a deferred revenue model.
	Miles Earned in Conjunction with Flights
	In the case of the sale of air services, the Company recognizes a portion of the ticket sales as revenue when the air transportation occurs and defers a portion of the ticket sale representing the value of the related miles as a multiple-deliverable revenue arrangement.
	The Company determines the estimated selling price of the air transportation and miles as if each element is sold on a separate basis. The total consideration from each ticket sale is then allocated to each of these elements individually on a pro rata basis. The Company’s estimated selling price of miles is based on the price we sell miles to Star Alliance partners in our reciprocal frequent flyer agreements as the best estimate of selling price for these miles.
	On December 9, 2013, US Airways and American Airlines closed their merger transaction and, as a result of the merger transaction, we anticipate US Airways will exit Star Alliance on March 30, 2014. Effective with the exit date of US Airways from Star Alliance, the Company will update its estimated selling price for miles to using the equivalent ticket value less fulfillment discount, as the estimated selling price for miles. The equivalent ticket value used as the basis for the estimated selling price of miles is based on the prior 12 months’ weighted average equivalent ticket value of similar fares as those used to settle award redemptions while taking into consideration such factors as redemption pattern, cabin class and geographic region. Management believes this change is a change in estimate, and as such, the change will be applied on a prospective basis. The estimated impact of this change on consolidated revenue is not expected to be material in 2014.
	Co-branded Credit Card Partner Mileage Sales
	United also has a significant contract to sell frequent flyer miles to its co-branded credit card partner, Chase Bank USA, N.A. (“Chase”). On June 9, 2011, this contract was modified and United entered into The Consolidated Amended and Restated Co-Branded Card Marketing Services Agreement (the “Co-Brand Agreement”) with Chase.
	United identified five revenue elements in the Co-Brand Agreement: the air transportation element represented by the value of the mile (generally resulting from its redemption for future air transportation and whose fair value is described above); use of the United brand and access to frequent flyer member lists; advertising; baggage services; and airport lounge usage (together, excluding “the air transportation element”, the “marketing-related deliverables”).
	The fair value of the elements is determined using management’s estimated selling price of each element. The objective of using the estimated selling price based methodology is to determine the price at which we would transact a sale if the product or service were sold on a stand-alone basis. Accordingly, we determine our best estimate of selling price by considering multiple inputs and methods including, but not limited to, discounted cash flows, brand value, volume discounts, published selling prices, number of miles awarded and number of miles redeemed. The Company estimated the selling prices and volumes over the term of the Co-Brand Agreement in order to determine the allocation of proceeds to each of the multiple elements to be delivered. The method for determining the selling price of the mile component is changing March 30, 2014, as described above. We also evaluate volumes on an annual basis, which may result in a change in the allocation of estimated selling price on a prospective basis.
	The Company records passenger revenue related to the air transportation element when the transportation is delivered. The other elements are generally recognized as Other operating revenue when earned.
	Expiration of Miles
	The Company accounts for miles sold and awarded that will never be redeemed by program members, which we refer to as breakage. The Company reviews its breakage estimates annually based upon the latest available information regarding redemption and expiration patterns. The Company re-evaluated its population breakage estimates for a portion of its miles, which were previously not subject to an expiration policy, and increased the estimate of miles in the population expected to ultimately expire.
	The Company’s estimate of the expected expiration of miles requires significant management judgment. Current and future changes to expiration assumptions or to the expiration policy, or to program rules and program redemption opportunities, may result in material changes to the deferred revenue balance as well as recognized revenues from the programs. Effective March 30, 2014, the Company will incorporate a fulfillment discount into its best estimate of selling price which incorporates the expected redemption of miles.
	Other Information
	The following table provides additional information related to the frequent flyer program (in millions):
	Year Ended		Cash Proceeds		Other Revenue		Increase in Frequent		Increase
	December 31,		from Miles Sold		Recognized Upon		Flyer Deferred		(Decrease)  in
					Award of Miles		Revenue for Miles		Advanced
					to Third-Party		Awarded (b)		Purchase of
					Customers (a)				Miles (c)
	2013		$	2,903	$	903	$	2,174	$	-174
	2012			2,852		816		2,036		—
	2011			3,121		566		2,357		198
	(a) This amount represents other revenue recognized during the period from the sale of miles to third parties, representing the marketing-related deliverable services component of the sale.
	(b) This amount represents the increase to frequent flyer deferred revenue during the period.
	(c) This amount represents the net increase (decrease) in the advance purchase of miles obligation due to cash payments for the sale of miles in excess of (less than) miles awarded to customers.
	(d)	Cash and Cash Equivalents and Restricted Cash— Highly liquid investments with a maturity of three months or less on their acquisition date are classified as cash and cash equivalents.
	Restricted cash primarily includes cash collateral associated with workers’ compensation obligations, reserves for institutions that process credit card ticket sales and cash collateral received from fuel hedge counterparties. Restricted cash is classified as short-term or long-term in the consolidated balance sheets based on the expected timing of return of the assets to the Company. Airline industry practice includes classification of restricted cash flows as either investing cash flows or operating cash flows. Cash flows related to restricted cash activity are classified as investing activities because the Company considers restricted cash arising from these activities similar to an investment.
	(e)	Short-term Investments—Short-term investments are classified as available-for-sale and are stated at fair value. Realized gains and losses on sales of investments are reflected in nonoperating income (expense) in the consolidated statements of operations. Unrealized gains and losses on available-for-sale securities are reflected as a component of accumulated other comprehensive income/loss.
	(f)	Aircraft Fuel, Spare Parts and Supplies—The Company accounts for aircraft fuel, spare parts and supplies at average cost and provides an obsolescence allowance for aircraft spare parts and supplies.
	(g)	Property and Equipment—The Company records additions to owned operating property and equipment at cost when acquired. Property under capital leases and the related obligation for future lease payments are recorded at an amount equal to the initial present value of those lease payments. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized as property and equipment. It is the Company’s policy to record compensation from delays in delivery of aircraft as a reduction of the cost of the related aircraft.
	Depreciation and amortization of owned depreciable assets is based on the straight-line method over the assets’ estimated useful lives. Leasehold improvements are amortized over the remaining term of the lease, including estimated facility renewal options when renewal is reasonably assured at key airports, or the estimated useful life of the related asset, whichever is less. Properties under capital leases are amortized on the straight-line method over the life of the lease or, in the case of certain aircraft, over their estimated useful lives, whichever is shorter. Amortization of capital lease assets is included in depreciation and amortization expense. The estimated useful lives of property and equipment are as follows:
			Estimated Useful Life (in years)
	Aircraft and related rotable parts			25 to 30
	Buildings			25 to 45
	Other property and equipment			4 to 15
	Computer software			5
	Building improvements			1 to 40
	As of December 31, 2013 and 2012, the Company had a carrying value of computer software of $290 million and $302 million, respectively. For the years ended December 31, 2013, 2012 and 2011, the Company’s depreciation expense related to computer software was $72 million, $81 million and $133 million, respectively. Aircraft and aircraft parts were assumed to have residual values with a range of 10% to 11% of original cost, depending on type, and other categories of property and equipment were assumed to have no residual value.
	(h)	Maintenance and Repairs—The cost of maintenance and repairs, including the cost of minor replacements, is charged to expense as incurred, except for costs incurred under our power-by-the-hour (“PBTH”) engine maintenance agreements. PBTH contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Under PBTH agreements, the Company recognizes expense at a level rate per engine hour, unless the level of service effort and the related payments during the period are substantially consistent, in which case the Company recognizes expense based on the amounts paid.
	(i)	Lease Fair Value Adjustments—Lease fair value adjustments, which arose from recording operating leases at fair value under fresh start accounting or the Merger, are amortized on a straight line basis over the related lease term.
	(j)	Regional Capacity Purchase—Payments made to regional carriers under CPAs are reported in Regional capacity purchase in our consolidated statements of operations.
	(k)	Advertising—Advertising costs, which are included in Other operating expenses, are expensed as incurred. Advertising expenses were $178 million, $154 million and $142 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	(l)	Intangibles—The Company has finite-lived and indefinite-lived intangible assets, including goodwill. As of December 31, 2013, goodwill represents the excess purchase price over the fair values of tangible and identifiable intangible assets acquired and liabilities assumed from Continental in the Merger. Finite-lived intangible assets are amortized over their estimated useful lives. Goodwill and indefinite-lived intangible assets are not amortized but are reviewed for impairment annually or more frequently if events or circumstances indicate that the asset may be impaired. Goodwill and indefinite-lived assets are reviewed for impairment on an annual basis as of October 1, or on an interim basis whenever a triggering event occurs. See Notes 2 and 17 for additional information related to intangibles.
	(m)	Long-Lived Asset Impairments—The Company evaluates the carrying value of long-lived assets and intangible assets subject to amortization whenever events or changes in circumstances indicate that an impairment may exist. For purposes of this testing, the Company has generally identified the aircraft fleet type as the lowest level of identifiable cash flows for purposes of testing aircraft for impairment. An impairment charge is recognized when the asset’s carrying value exceeds its net undiscounted future cash flows and its fair market value. The amount of the charge is the difference between the asset’s carrying value and fair market value. See Note 17 for information related to asset impairments.
	(n)	Share-Based Compensation—The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. The resulting cost is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period. Obligations for restricted stock units (“RSUs”) are remeasured at fair value throughout the requisite service period on the last day of each reporting period based upon UAL’s stock price. In addition to the service requirement, certain RSUs have performance metrics that must be achieved prior to vesting. These awards are accrued based on the expected level of achievement at each reporting period. A cumulative adjustment is recorded on the last day of each reporting period to adjust compensation expense based on both UAL’s stock price and the then current level of expected performance achievement for the performance-based awards. See Note 5 for additional information on UAL’s share-based compensation plans.
	(o)	Ticket Taxes—Certain governmental taxes are imposed on the Company’s ticket sales through a fee included in ticket prices. The Company collects these fees and remits them to the appropriate government agency. These fees are recorded on a net basis (excluded from operating revenue).
	(p)	Retirement of Leased Aircraft—The Company accrues for estimated lease costs over the remaining term of the lease at the present value of future minimum lease payments, net of estimated sublease rentals (if any), in the period that aircraft are permanently removed from service. When reasonably estimable and probable, the Company estimates maintenance lease return condition obligations for items such as minimum aircraft and engine conditions specified in leases and accrues these amounts over the lease term while the aircraft are operating, and any remaining unrecognized estimated obligations are accrued in the period that an aircraft is removed from service.
	(q)	Uncertain Income Tax Positions—The Company has recorded reserves for income taxes and associated interest that may become payable in future years. Although management believes that its positions taken on income tax matters are reasonable, the Company nevertheless has established tax and interest reserves in recognition that various taxing authorities may challenge certain of the positions taken by the Company, potentially resulting in additional liabilities for taxes and interest. The Company’s uncertain tax position reserves are reviewed periodically and are adjusted as events occur that affect its estimates, such as the availability of new information, the lapsing of applicable statutes of limitation, the conclusion of tax audits, the measurement of additional estimated liability, the identification of new tax matters, the release of administrative tax guidance affecting its estimates of tax liabilities, or the rendering of relevant court decisions. See Note 7 for further information related to uncertain income tax positions.
	(r)	Labor Costs—The Company records expenses associated with amendable labor agreements when the employee group has earned the compensation and the amounts are probable and estimable. These include costs associated with lump sum cash payments that would be made in conjunction with the ratification of labor agreements. To the extent these upfront costs are in lieu of future pay increases, they would be capitalized and amortized over the term of the labor agreements. If not, these amounts would be expensed once earned and when they become probable and estimable.
	(s)	Third-Party Business—The Company has third-party business revenue that includes fuel sales, catering, ground handling, maintenance services and frequent flyer award non-air redemptions, and third-party business revenue is recorded in other revenue. The Company has a contract to sell aircraft fuel to a third party which is earnings-neutral but results in revenue and expense, specifically cost of sale which is unrelated to the operation of the airline. The Company also incurs third-party business expenses, such as maintenance, ground handling and catering services for third parties, fuel sales and non-air mileage redemptions, and those third-party business expenses are recorded in Other operating expenses.
	(t)	Related party receivables—United has receivables from affiliates of $232 million that are classified against stockholder’s equity as of December 31, 2013 as a result of an anticipated distribution of the amount via an equity transaction planned in early 2014.
	(u)	Recently Issued Accounting Standards—In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update No. 2013-02 (“ASU 2013-02”), Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. Some of the key amendments require the Company to present, either on the face of the statement of operations or in the notes to the consolidated financial statements, the effects on the line items of net income of significant amounts reclassified out of accumulated other comprehensive income, but only if the amount reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period. For amounts that are not required to be reclassified in their entirety to net income, the Company is required to cross-reference to other disclosures that provide additional detail about those amounts. ASU 2013-02 became effective for the Company’s annual and interim periods beginning January 1, 2013, and the required disclosures are included in Note 6 of this report.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Other Intangible Assets	'
	NOTE 2 - GOODWILL AND OTHER INTANGIBLE ASSETS
	The following table presents information about the Company’s goodwill and other intangible assets at December 31 (in millions):
			2013				2012
	Item	Asset life (a)	Gross Carrying		Accumulated		Gross Carrying		Accumulated
			Amount		Amortization		Amount		Amortization
	Goodwill		$	4,523			$	4,523
	Finite-lived intangible assets
	Airport slots and gates	8	$	98	$	88	$	99	$	75
	Hubs	20		145		59		145		52
	Patents and tradenames	3		108		108		108		99
	Frequent flyer database (b)	22		1,177		536		1,177		447
	Contracts	13		167		86		167		75
	Other	25		109		56		109		44
	Total		$	1,804	$	933	$	1,805	$	792
	Indefinite-lived intangible assets
	Airport slots and gates		$	963			$	981
	Route authorities			1,605				1,606
	Tradenames and logos			593				593
	Alliances			404				404
	Total		$	3,565			$	3,584
	(a) Weighted average life expressed in years.
	(b) The frequent flyer database is amortized based on an accelerated amortization schedule to reflect utilization of the assets. Estimated cash flows correlating to the expected attrition rate of customers in the frequent flyer database is considered in the determination of the amortization schedules.
	Amortization expense in 2013, 2012 and 2011 was $142 million, $121 million and $169 million, respectively. Projected amortization expense in 2014, 2015, 2016, 2017 and 2018 is $128 million, $106 million, $92 million, $81 million and $72 million, respectively.
	See Note 17 for information related to impairment of intangible assets.

Common_Stockholders_Equity_and

Common Stockholders' Equity and Preferred Securities	12 Months Ended
	Dec. 31, 2013
Common Stockholders' Equity and Preferred Securities	'
	NOTE 3 - COMMON STOCKHOLDERS’ EQUITY AND PREFERRED SECURITIES
	At December 31, 2013, approximately 44 million shares of UAL’s common stock were reserved for future issuance related to the conversion of convertible debt securities and the issuance of equity based awards under the Company’s incentive compensation plans.
	As of December 31, 2013, UAL had two shares of junior preferred stock (par value $0.01 per share) outstanding. In addition, UAL is authorized to issue 250 million shares of preferred stock (without par value) under UAL’s amended and restated certificate of incorporation.
	In January and February 2014, holders of substantially all of the remaining $156 million outstanding principal amount of the 4.5% Senior Limited-Subordination Convertible Notes due 2021 (the “4.5% Notes”) exercised their right to convert such notes into shares of UAL common stock at a conversion rate of 30.6419 shares of UAL common stock per $1,000 principal amount of 4.5% Notes. See Note 11 for information related to exercises of the 4.5% Notes.

Earnings_Loss_Per_Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2013
Earnings (Loss) Per Share	'
	NOTE 4 - EARNINGS (LOSS) PER SHARE
	The computations of UAL’s basic and diluted earnings (loss) per share and the number of securities that have been excluded from the computation of diluted earnings per share amounts because they were antidilutive are set forth below (in millions, except per share amounts):
		2013		2012		2011
	Basic earnings (loss) per share:
	Net income (loss)	$	571	$	-723	$	840
	Less: Income allocable to participating securities		-2		—		-3
	Earnings (loss) available to common stockholders	$	569	$	-723	$	837
	Basic weighted-average shares outstanding		348		331		329
	Earnings (loss) per share, basic	$	1.64	$	-2.18	$	2.54
	Diluted earnings (loss) per share:
	Earnings (loss) available to common stockholders	$	569	$	-723	$	837
	Effect of dilutive securities		26		—		27
	Earnings (loss) available to common stockholders including the effect of dilutive securities	$	595	$	-723	$	864
	Diluted shares outstanding:
	Basic weighted-average shares outstanding		348		331		329
	Effect of convertible notes		42		—		52
	Effect of employee stock options		—		—		2
	Diluted weighted-average shares outstanding		390		331		383
	Earnings (loss) per share, diluted	$	1.53	$	-2.18	$	2.26
	Potentially dilutive shares excluded from diluted per share amounts:
	Restricted stock and stock options		3		5		6
	Convertible notes		4		61		15
			7		66		21
	See Note 11 for information related to the exchange of shares for redemption of convertible debt.

ShareBased_Compensation_Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 31, 2013
Share-Based Compensation Plans	'
	NOTE 5 - SHARE-BASED COMPENSATION PLANS
	UAL maintains several share-based compensation plans. These plans provide for grants of qualified and non-qualified stock options, stock appreciation rights, restricted stock awards, RSUs, performance compensation awards, performance units, cash incentive awards and other types of equity-based and equity-related awards.
	All awards are recorded as equity or a liability in the Company’s consolidated balance sheets. The share-based compensation expense is directly recorded in salaries and related costs or integration-related expense.
	In February 2013, UAL granted share-based compensation awards pursuant to the United Continental Holdings, Inc. 2008 Incentive Compensation Plan. These share-based compensation awards include approximately 0.5 million shares of restricted stock and 0.5 million of RSUs that vest pro-rata over three years on the anniversary of the grant date. The time vested RSUs are cash-settled based on the 20-day average closing price of UAL common stock immediately prior to the vesting date. In addition, UAL granted 1.3 million RSUs that will vest based on UAL’s return on invested capital for the three years ending December 31, 2015. If this performance condition is achieved, cash payments will be made after the end of the performance period based on the 20-day average closing price of UAL common stock immediately prior to the vesting date. The Company accounts for the RSUs as liability awards.
	The following table provides information related to UAL’s share-based compensation plan cost for the years ended December 31 (in millions):
		2013		2012		2011
	Compensation cost: (a)
	RSUs	$	88	$	37	$	18
	Restricted stock		11		13		12
	Share-based awards converted to cash awards		1		6		19
	Stock options		—		1		5
	Total	$	100	$	57	$	54
	(a) All compensation cost is recorded to Salaries and related costs, with the exception of $9 million, $9 million and $17 million in 2013, 2012 and 2011, respectively, that was recorded in integration-related costs as a component of special charges.
	The table below summarizes UAL’s unearned compensation and weighted-average remaining period to recognize costs for all outstanding share-based awards for the year ended December 31, 2013 (in millions, except as noted):
		Unearned		Weighted-
		Compensation		Average
				Remaining
				Period (in
				years)
	RSUs	$	36		1.3
	Restricted stock		8		1.4
	Stock options		—		0.6
	Total	$	44
	RSUs and Restricted Stock. All outstanding RSUs are settled in cash. As of December 31, 2013, UAL had recorded a liability of $118 million related to its RSUs. UAL paid $29 million, $35 million and $57 million related to its share-based liabilities during 2013, 2012 and 2011, respectively.
	The table below summarizes UAL’s RSUs and restricted stock activity for the years ended December 31 (shares in millions):
		RSUs		Restricted Stock		Weighted-
						Average
						Grant  Price
	Non-vested at December 31, 2010		—		1	$	17.20
	Granted		4		1		23.87
	Vested		—		-1		22.26
	Surrendered		-1		—		23.95
	Non-vested at December 31, 2011		3		1		23.33
	Granted		2		1		24.01
	Vested		—		-1		23.05
	Surrendered		-1		—		24.01
	Non-vested at December 31, 2012		4		1		23.94
	Granted		2		1		25.98
	Vested		-1		-1		23.93
	Surrendered		—		—		24.76
	Non-vested at December 31, 2013		5		1		25.02
	The fair value of RSUs and restricted stock vested in 2013, 2012 and 2011 was $22 million, $27 million and $7 million, respectively. The fair value of the restricted stock awards was primarily based upon the UAL common stock price on the date of grant. These awards are accounted for as equity awards. The fair value of the RSUs was based on the UAL common stock price as of the last day preceding the settlement date. These awards were accounted for as liability awards. Restricted stock vesting and the recognition of the expense is similar to the stock option vesting described below.
	Stock Options. UAL has not granted any stock options since 2010. Historically, stock options were awarded with exercise prices equal to the fair market value of UAL’s common stock on the date of grant. UAL stock options generally vest over a period of either three or four years and have a contractual life of 10 years. The Continental stock options assumed by UAL at the Merger generally have an original contractual life of five years (management level employee options) or 10 years (outside directors). Expense related to each portion of an option grant is recognized on a straight-line basis over the specific vesting period for those options.
	The table below summarizes UAL stock option activity for the years ended December 31 (in millions, except as noted):
		Options		Weighted-		Weighted-		Aggregate
				Average		Average		Intrinsic Value
				Exercise Price		Remaining
						Contractual
						Life (in years)
	Outstanding at December 31, 2010		11	$	21.70
	Exercised		-2		10.77			$	33
	Surrendered		-2		29.07
	Outstanding at December 31, 2011		7		23.80
	Exercised		-1		12.42				14
	Surrendered		-1		30.50
	Outstanding at December 31, 2012		5		25.60
	Exercised		-2		16.28				27
	Surrendered		—		27.49
	Outstanding at December 31, 2013		3		31.63		2.2		18
	Exercisable at December 31, 2013		3		32.00		2.2		16
	The fair value of options is determined at the grant date, and at the Merger date in the case of Continental options, using a Black Scholes option pricing model, which requires the Company to make several assumptions. The risk-free interest rate is based on the U.S. treasury yield curve in effect for the expected term of the option at the time of grant. The dividend yield on UAL’s common stock was assumed to be zero since UAL did not have any plans to pay dividends at the time of the option grants.
	The volatility assumptions were based upon historical volatilities of UAL and other comparable airlines whose shares are traded using daily stock price returns equivalent to the contractual term of the option. In addition, implied volatility data for both UAL and other comparable airlines, using current exchange-traded options, was utilized.
	The expected lives of the options were determined based upon either a simplified assumption that the option will be exercised evenly from vesting to expiration or estimated using historical experience for the assumed options. The terms of certain awards do not provide for the acceleration of vesting upon retirement. In addition, certain awards and the assumed options awarded to employees that are retirement eligible either at the grant date or within the vesting period are considered vested at the respective retirement eligibility date.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss)	'
	NOTE 6 - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
	The tables below present the components of the Company’s accumulated other comprehensive income (loss) (“AOCI”), net of tax (in millions):
	UAL (a)		Pension and			Unrealized		Other		Total
			Other			Gains (Losses)
			Postretirement			on Derivatives
			Unrecognized
			Actuarial
			Gains (Losses)
			and Prior
			Service Cost
	Balance at December 31, 2010		$	152		$	240	$	-5	$	387
	Other comprehensive loss before reclassifications			-440			163		—		-277
	Amounts reclassified from accumulated other comprehensive income			-24			-503		—		-527
	Net current-period other comprehensive income (loss)			-464			-340		—		-804
	Balance at December 31, 2011		$	-312		$	-100	$	-5	$	-417
	Other comprehensive loss before reclassifications			-747			-51		11		-787
	Amounts reclassified from accumulated other comprehensive income			17			141		—		158
	Net current-period other comprehensive income (loss)			-730			90		11		-629
	Balance at December 31, 2012		$	-1,042		$	-10	$	6	$	(1,046)
	Other comprehensive income before reclassifications			1,584	(b)		39		7		1,630
	Amounts reclassified from accumulated other comprehensive income			42			-18		—		24
	Net current-period other comprehensive income (loss)			1,626			21		7		1,654
	Balance at December 31, 2013		$	584		$	11	$	13	$	608
	Details about AOCI Components		Amount Reclassified from AOCI to							Affected Line Item in
			Income							the Statement Where
										Net Income is Presented
			Year Ended December 31,
			2013			2012		2011
	Derivatives designated as cash flow hedges
	Fuel contracts-reclassifications of (gains) losses into earnings (c)		$	-18		$	141	$	-503	Aircraft fuel
	Amortization of pension and post-retirement items
	Amortization of unrecognized (gains) losses and prior service cost and the effect of curtailments and settlements (c) (d)		$	42		$	17	$	-24	Salaries and related costs
	(a) UAL and United amounts are substantially the same except for an additional $6 million of income tax benefit at United in 2013. In addition, United had additional (losses) gains related to investments and other of $(2) million, $1 million and $1 million in 2011, 2012 and 2013, respectively.
	(b) For 2013, prior service credits increased by $331 million and actuarial gains increased by approximately $1.3 billion. Amounts for 2012 and 2011 were not material.
	(c)	Income tax expense offset by Company’s valuation allowance.
	(d) This accumulated other comprehensive income component is included in the computation of net periodic pension costs (see Note 8 of this report for additional details).

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Taxes	'
	NOTE 7 - INCOME TAXES
	The significant components of the income tax expense (benefit) are as follows (in millions):
	2013	UAL		United
	Current	$	-18	$	-18
	Deferred		-14		1
		$	-32	$	-17
	2012
	Current	$	-14	$	-9
	Deferred		13		13
		$	-1	$	4
	2011
	Current	$	11	$	3
	Deferred		-6		-5
		$	5	$	-2
	The income tax provision differed from amounts computed at the statutory federal income tax rate, as follows (in millions):
	Year ended December 31, 2013	UAL		United
	Income tax provision at statutory rate	$	189	$	223
	State income taxes, net of federal income tax		5		5
	Foreign income taxes		3		3
	Nondeductible employee meals		15		15
	Nondeductible interest expense		—		—
	Derivative market adjustment		—		-24
	Nondeductible compensation		3		3
	State rate change		-33		-33
	Valuation allowance		-219		-229
	Other, net		5		20
		$	-32	$	-17
	Year ended December 31, 2012
	Income tax provision at statutory rate	$	-253	$	-230
	State income taxes, net of federal income tax		-15		-7
	Foreign income taxes		7		7
	Nondeductible employee meals		12		12
	Nondeductible interest expense		19		19
	Derivative market adjustment		—		-15
	Nondeductible compensation		5		5
	Valuation allowance		234		223
	Other, net		-10		-10
		$	-1	$	4
	Year Ended December 31, 2011
	Income tax provision at statutory rate	$	298	$	299
	State income taxes, net of federal income tax		-19		-17
	Nondeductible acquisition costs		-17		-17
	Nondeductible employee meals		12		12
	Nondeductible interest expense		13		13
	Derivative market adjustment		—		10
	Nondeductible compensation		9		10
	Valuation allowance		-294		-315
	Other, net		3		3
		$	5	$	-2
	State tax benefit recorded in 2011 resulted from certain adjustments to existing state tax net operating losses, and such benefit was fully offset by an increase in the valuation allowance.
	Temporary differences and carryforwards that give rise to deferred tax assets and liabilities at December 31, 2013 and 2012 were as follows (in millions):
		UAL				United
		December 31,				December 31,
		2013		2012		2013		2012
	Deferred income tax asset (liability):
	Federal and state net operating loss (“NOL”) carryforwards	$	3,221	$	3,025	$	3,158	$	2,957
	Frequent flyer deferred revenue		2,254		2,425		2,254		2,426
	Employee benefits, including pension, postretirement, medical and the Pension Benefit Guaranty Corporation (“PBGC”) notes		1,701		2,488		1,701		2,491
	Lease fair value adjustment		123		259		123		259
	AMT credit carryforwards		233		251		233		251
	Other assets		217		947		217		882
	Less: Valuation allowance		-3,806		-4,603		-3,776		-4,503
	Total deferred tax assets (a)	$	3,943	$	4,792	$	3,910	$	4,763
Depreciation, capitalized interest and other	$	-3,201	$	-3,705	$	-3,201	$	-3,702
Intangibles		-1,585		-1,578		-1,585		-1,579
Other liabilities		-144		-509		-111		-406
Total deferred tax liabilities	$	-4,930	$	-5,792	$	-4,897	$	-5,687
Net deferred tax liability (a)	$	-987	$	-1,000	$	-987	$	-924
(a) During 2013, UAL identified adjustments to the components of the deferred taxes. As a result of this analysis, changes in deferred tax assets and liabilities occurred, and are reflected in 2013 deferred tax balances. UAL and United increased their valuation allowance to reflect these adjustments by $84 million and $163 million, respectively. United separately identified an adjustment of $68 million to increase its deferred tax liability with an offset to United-only equity to correct an error made in prior years. This item did not affect the consolidated accounts of UAL. It was corrected in the current period as it was not considered material to United’s prior year reported financial position.
United and its domestic consolidated subsidiaries file a consolidated federal income tax return with UAL. Under an intercompany tax allocation policy, United and its subsidiaries compute, record and pay UAL for their own tax liability as if they were separate companies filing separate returns. In determining their own tax liabilities, United and each of its subsidiaries take into account all tax credits or benefits generated and utilized as separate companies and they are each compensated for the aforementioned tax benefits only if they would be able to use those benefits on a separate company basis.
In addition to the deferred tax assets listed in the table above, UAL has an $800 million unrecorded tax benefit at December 31, 2013, primarily attributable to the difference between the amount of the financial statement expense and the allowable tax deduction for UAL’s common stock issued to certain unsecured creditors and employees pursuant to UAL Corporation’s Chapter 11 bankruptcy protection. This unrecorded tax benefit is accounted for by analogy to Accounting Standards Codification Topic 718 which requires recognition of the tax benefit to be deferred until it is realized as a reduction of taxes payable. Although not recognized for financial reporting purposes, this unrecognized tax benefit is available to reduce future income and is incorporated into the disclosed amounts of our federal and state NOL carryforwards, which are discussed below.
The federal and state NOL carryforwards relate to prior years’ NOLs, which may be used to reduce tax liabilities in future years. These tax benefits are mostly attributable to federal pre-tax NOL carryforwards of $10.9 billion for UAL (including the NOLs discussed in the preceding paragraph). If not utilized these federal pre-tax NOLs will expire as follows (in billions): $1.4 in 2022, $1.9 in 2023, $2.4 in 2024, $2.0 in 2025 and $3.2 after 2025. In addition, the majority of state tax benefits of the net operating losses of $168 million for UAL expires over a five to 20-year period.
Both UAL Corporation and Continental experienced an “ownership change” as defined under Section 382 of the Internal Revenue Code of 1986, as amended, as a result of the Merger. However, the Company does not expect these ownership changes to significantly limit its ability to use its NOL and alternative minimum tax (“AMT”) credit carryforwards in the carryforward period because the size of the limitation exceeds our NOL and AMT credit carryforwards.
The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income (including the reversals of deferred tax liabilities) during the periods in which those deferred tax assets will become deductible. The Company’s management assesses available positive and negative evidence regarding the realizability of its deferred tax assets and records a valuation allowance when it is more likely than not that deferred tax assets will not be realized. To form a conclusion, management considers positive evidence in the form of reversing temporary differences, projections of future taxable income and tax planning strategies, and negative evidence such as current period and cumulative losses. Although the Company was not in a three-year cumulative loss position at the end of 2013, management determined that the loss in 2012, the overall modest level of cumulative pretax income in the three years ended December 31, 2013 of 0.6% of total revenues in that period and the uncertainty associated with projecting future taxable income supported the conclusion that the valuation allowance was still necessary. Management will continue to evaluate future financial performance to determine whether such performance is both sustained and significant enough to provide sufficient evidence to support reversal of the valuation allowance.
The December 31, 2013 valuation allowances of $3.8 billion for both UAL and United, if reversed in future years will reduce income tax expense. The current valuation allowance reflects decreases from December 31, 2012 of $797 million and $727 million for UAL and United, respectively, including amounts charged directly to other comprehensive income.
The Company’s unrecognized tax benefits related to uncertain tax positions were $14 million, $19 million and $24 million at 2013, 2012 and 2011, respectively. Included in the ending balance at 2013 is $12 million that would affect the Company’s effective tax rate if recognized. The Company does not expect significant increases or decreases in their unrecognized tax benefits within the next twelve months.
There are no significant amounts included in the balance at December 31, 2013 for tax positions for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility.
The Company records penalties and interest relating to uncertain tax positions in Other operating expense and Interest expense, respectively, in its consolidated statements of operations. The Company has not recorded any significant expense or liabilities related to interest or penalties in its consolidated financial statements.
The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits related to the Company’s uncertain tax positions (in millions):
	2013		2012		2011
Balance at January 1,	$	19	$	24	$	32
Decrease in unrecognized tax benefits relating to settlements with taxing authorities		—		-12		—
Increase (decrease) in unrecognized tax benefits as a result of tax positions taken during a prior period		—		8		-9
Decrease in unrecognized tax benefits relating from a lapse of the statute of limitations		-5		-1		—
Increase in unrecognized tax benefits as a result of tax positions taken during the current period		—		—		1
Balance at December 31,	$	14	$	19	$	24
The Company’s federal income tax returns for tax years after 2002 remain subject to examination by the Internal Revenue Service (“IRS”) and state taxing jurisdictions. Continental’s federal income tax returns for tax years after 2001 remain subject to examination by the IRS and state taxing jurisdictions. In 2013, the IRS concluded an audit of 2010 through 2011 for UAL without any material adjustments to the financial statements.

Pension_and_Other_Postretireme

Pension and Other Postretirement Plans	12 Months Ended
	Dec. 31, 2013
Pension and Other Postretirement Plans	'
	NOTE 8 - PENSION AND OTHER POSTRETIREMENT PLANS
	The following summarizes the significant pension and other postretirement plans of United:
	Pension Plans
	United maintains two primary defined benefit pension plans, one covering certain pilot employees and another covering certain U.S. non-pilot employees. Each of these plans provide benefits based on a combination of years of benefit accruals service and an employee’s final average compensation. Additional benefit accruals were frozen under the plan covering certain pilot employees during 2005 and management and administrative employees as of December 31, 2013 at which time any existing accrued benefits for those employees were preserved. Benefit accruals for certain non-pilot employees under its other primary defined benefit pension plan continue. United maintains additional defined benefit pension plans, which cover certain international employees.
	Other Postretirement Plans
	We maintain postretirement medical programs which provide medical benefits to certain retirees and eligible dependents, as well as life insurance benefits to certain retirees participating in the plan. Benefits provided are subject to applicable contributions, co-payments, deductible and other limits as described in the specific plan documentation.
	During 2013, the Company experienced significant changes in its benefit obligations related to its primary defined benefit pension plans and postretirement medical programs. The significant changes resulted from the reduction or elimination of benefits for certain work groups including elimination of the postretirement medical benefits for all management and administrative employees and only those International Association of Machinists (“IAM”) employees with less than 20 years of service. Additionally, future accruals for defined benefit pension benefits for management and administrative employees were eliminated effective December 31, 2013. All of these changes are reflected in the December 31, 2013 obligation. In addition, certain key actuarial changes resulted in an additional net reduction of the pension and postretirement medical benefit obligations, principally market increases in discount rates, changes in participation and retirement rates for retiree medical plans (driven primarily by the actual experience in pilot retirement rates resulting from a change of the mandatory pilot retirement age to 65), partially offset by increases in anticipated salary scale for the pension plan, and an increase in health care trend rates for postretirement medical plans.
	Changes in benefits that either qualified as curtailments (which reduced prior actuarial losses) or negative plan amendments are detailed in the tables below. Actuarial assumption changes are reflected as a component of the net actuarial gains/(losses) during 2013. These amounts will be amortized over the average remaining service life of the covered active employees or the average life expectancy of inactive participants and will reduce 2013 pension and retiree medical expense as described below.
	The following table sets forth the reconciliation of the beginning and ending balances of the benefit obligation and plan assets, the funded status and the amounts recognized in these financial statements for the defined benefit and other postretirement plans (in millions):
		Pension Benefits
		Year Ended			Year Ended
		December 31, 2013			December 31, 2012
	Accumulated benefit obligation:	$	3,383		$	3,978
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year	$	4,526		$	3,708
	Service cost		121			99
	Interest cost		191			184
	Actuarial (gain) loss		-464			702
	Gross benefits paid and settlements		-269			-162
	Curtailments		-84			—
	Other		-21			-5
	Projected benefit obligation at end of year	$	4,000		$	4,526
	Change in plan assets:
	Fair value of plan assets at beginning of year	$	2,157		$	1,868
	Actual gain on plan assets		239			223
	Employer contributions		277			228
	Gross benefits paid and settlements		-269			-162
	Other		-7			—
	Fair value of plan assets at end of year	$	2,397		$	2,157
	Funded status—Net amount recognized	$	-1,603		$	-2,369
		Pension Benefits
		December 31, 2013			December 31, 2012
	Amounts recognized in the consolidated balance sheets consist of:
	Noncurrent asset	$	49		$	35
	Current liability		-2			-4
	Noncurrent liability		-1,650			-2,400
	Total liability	$	-1,603		$	-2,369
	Amounts recognized in accumulated other comprehensive income (loss) consist of:
	Net actuarial loss	$	-162		$	-826
	Prior service credit		—			2
	Total accumulated other comprehensive loss	$	-162		$	-824
		Other Postretirement Benefits
		Year Ended			Year Ended
		December 31, 2013			December 31, 2012
	Change in benefit obligation:
	Benefit obligation at beginning of year	$	2,743		$	2,541
	Service cost		52			50
	Interest cost		110			124
	Plan participants’ contributions		67			77
	Actuarial (gain) loss		-640			110
	Federal subsidy		7			13
	Plan amendments		-331			22
	Curtailments		8			—
	Gross benefits paid		-197			-194
	Benefit obligation at end of year	$	1,819		$	2,743
	Change in plan assets:
	Fair value of plan assets at beginning of year	$	58		$	58
	Actual return on plan assets		1			1
	Employer contributions		128			116
	Plan participants’ contributions		67			77
	Benefits paid		-197			-194
	Fair value of plan assets at end of year		57			58
	Funded status—Net amount recognized	$	-1,762		$	-2,685
	Other Postretirement Benefits
	December 31, 2013			December 31, 2012
Amounts recognized in the consolidated balance sheets consist of:
Current liability	$	-59		$	-71
Noncurrent liability		-1,703			-2,614
Total liability	$	-1,762		$	-2,685
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	$	555		$	-79
Prior service credit (cost)		306			-24
Total accumulated other comprehensive income (loss)	$	861		$	-103
The following information relates to all pension plans with an accumulated benefit obligation and a projected benefit obligation in excess of plan assets at December 31 (in millions):
	2013			2012
Projected benefit obligation	$	3,820		$	4,387
Accumulated benefit obligation		3,245			3,869
Fair value of plan assets		2,176			1,991
Net periodic benefit cost for the years ended December 31 included the following components (in millions):
	2013					2012				2011
	Pension			Other		Pension		Other		Pension				Other
	Benefits			Postretirement		Benefits		Postretirement		Benefits				Postretirement
				Benefits				Benefits						Benefits
Service cost	$	121		$	52	$	99	$	50	$	88			$	47
Interest cost		191			110		184		124		178				127
Expected return on plan assets		-163			-2		-138		-2		-140				-2
Curtailment loss		2			2		—		—		—				—
Amortization of prior service credits		—			-3		-1		—		-2				—
Settlement (gain) loss		-10			—		1		—		1				—
Amortization of unrecognized actuarial (gain) loss		48			3		21		-3		-20				-2
Net periodic benefit cost	$	189		$	162	$	166	$	169	$	105			$	170
The estimated amounts that will be amortized in 2014 for actuarial (gains) losses are as follows (in millions):
	Pension			Other
	Benefits			Postretirement
				Benefits
Actuarial (gain) loss to be reclassified from accumulated other comprehensive income into net periodic benefit cost	$	9		$	-46
The assumptions used for the benefit plans were as follows:
		Pension Benefits
Assumptions used to determine benefit obligations		2013			2012
Discount rate		5.09%			4.19%
Rate of compensation increase		3.49%			2.49%
Assumptions used to determine net expense
Discount rate		4.48%			5.02%
Expected return on plan assets		7.56%			7.54%
Rate of compensation increase		2.48%			2.48%
	Other Postretirement Benefits
Assumptions used to determine benefit obligations	2013			2012
Discount rate		4.94%			4.12%
Assumptions used to determine net expense
Discount rate		4.12%			4.92%
Expected return on plan assets		4.00%			4.00%
Health care cost trend rate assumed for next year		7.25%			6.75%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2020)		5.00%			5.00%
The Company selected the 2013 discount rate for each of its plans by using a hypothetical portfolio of high quality bonds at December 31, 2013, that would provide the necessary cash flows to match projected benefit payments.
We develop our expected long-term rate of return assumption for such plans based on historical experience and by evaluating input from the trustee managing the plans’ assets. Our expected long-term rate of return on plan assets for these plans is based on a target allocation of assets, which is based on our goal of earning the highest rate of return while maintaining risk at acceptable levels. The plans strive to have assets sufficiently diversified so that adverse or unexpected results from one security class will not have an unduly detrimental impact on the entire portfolio. Plan fiduciaries regularly review our actual asset allocation and the pension plans’ investments are periodically rebalanced to our targeted allocation when considered appropriate. United’s plan assets are allocated within the following guidelines:
	Percent of Total		Expected Long-Term
			Rate of Return
Equity securities	42-52    %		9.5    %
Fixed-income securities	26-34		5.5
Alternatives	15-21		7.5
Other	7-Mar		4.5
One-hundred percent of other postretirement plan assets are invested in a deposit administration fund.
Assumed health care cost trend rates have a significant effect on the amounts reported for the other postretirement plans. A 1% change in the assumed health care trend rate for the Company would have the following additional effects (in millions):
	1% Increase			1% Decrease
Effect on total service and interest cost for the year ended December 31, 2013	$	21		$	-17
Effect on postretirement benefit obligation at December 31, 2013		213			-186
A one percentage point decrease in the weighted average discount rate would increase the postretirement benefit liability by approximately $203 million and increase the estimated 2013 benefits expense by approximately $10 million.
Fair Value Information. Accounting standards require us to use valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are prioritized as follows:
Level 1	Unadjusted quoted prices in active markets for assets or liabilities identical to those to be reported at fair value
Level 2	Other inputs that are observable directly or indirectly, such as quoted prices for similar assets or liabilities or market-corroborated inputs
Level 3	Unobservable inputs for which there is little or no market data and which require us to develop our own assumptions about how market participants would price the assets or liabilities
The following tables present information about the United’s pension and other postretirement plan assets at December 31 (in millions):
	2013											2012
Pension Plan Assets:	Total			Level 1		Level 2		Level 3				Total				Level 1		Level 2		Level 3
Equity securities funds	$	1,158		$	389	$	769	$	—			$	1,034			$	383	$	651	$	—
Fixed-income securities		702			—		698		4				611				—		609		2
Alternatives		405			—		199		206				394				—		234		160
Insurance contract		26			—		—		26				36				—		—		36
Other investments		106			—		106		—				82				—		82		—
Total	$	2,397		$	389	$	1,772	$	236			$	2,157			$	383	$	1,576	$	198
Other Postretirement Benefit Plan Assets:
Deposit administration fund	$	57		$	—	$	—	$	57			$	58			$	—	$	—	$	58
Equity and Fixed-Income Securities. Equity securities include investments in both developed market and emerging market equity securities. Fixed-income securities include primarily U.S. and non-U.S. government fixed-income securities and U.S. and non-U.S corporate fixed-income securities along with asset-backed securities.
Insurance Contract and Deposit Administration Fund. Each of these investments are stable value investment products structured to provide investment income.
Alternatives. Alternative investments consist primarily of investments in hedge funds, real estate and private equity interests.
Other investments. Other investments consist primarily of investments in currency and commodity commingled funds.
The reconciliation of United’s defined benefit plan assets measured at fair value using unobservable inputs (Level 3) for the years ended December 31, 2013 and 2012 is as follows (in millions):
	2013			2012
Balance at beginning of year	$	256		$	249
Actual return on plan assets:
Sold during the year		15			—
Held at year end		7			-47
Purchases, sales, issuances and settlements (net)		15			54
Balance at end of year	$	293		$	256
Funding requirements for tax-qualified defined benefit pension plans are determined by government regulations. United’s contributions reflected above have satisfied its required contributions through the 2013 calendar year. Expected 2014 employer contributions to all of United’s pension and postretirement plans are $288 million and $120 million, respectively.
The estimated future benefit payments, net of expected participant contributions, in United’s pension plans and other postretirement benefit plans as of December 31, 2013 are as follows (in millions):
	Pension			Other		Other Postretirement—
				Postretirement		subsidy receipts
2014	$	247		$	122	$	6
2015		259			123		7
2016		265			126		7
2017		271			129		8
2018		268			132		9
Years 2019 – 2023		1,435			717		53
Defined Contribution Plans
Depending upon the employee group, employer contributions consist of matching contributions and/or non-elective employer contributions. United’s employer contribution percentages vary from 1% to 16% of eligible earnings depending on the terms of each plan. United recorded contributions to its defined contribution plans of $433 million, $330 million and $291 million in the years ended December 31, 2013, 2012 and 2011, respectively.
Multi-Employer Plans
United’s participation in the IAM National Pension Plan (“IAM Plan”) for the annual period ended December 31, 2013 is outlined in the table below. There have been no significant changes that affect the comparability of 2013 and 2012 contributions. The risks of participating in these multi-employer plans are different from single-employer plans, as United may be subject to additional risks that others do not meet their obligations, which in certain circumstances could revert to United. The IAM Plan reported $351 million in employers’ contributions for the year ended December 31, 2012. For 2012, the Company’s contributions to the IAM Plan represented more than 5% of total contributions to the IAM Plan.
Pension Fund	IAM National Pension Fund
EIN/ Pension Plan Number	51-6031295 - 002
Pension Protection Act Zone Status (2013 and 2012)*	Green Zone
FIP/RP Status Pending/Implemented	No
United’s Contributions	$38 million, $36 million and $34 million in the years ended December 31, 2013, 2012 and 2011, respectively
Surcharge Imposed	No
Expiration Date of Collective Bargaining Agreement	N/A
* Plans in the green zone are at least 80 percent funded.
At the date the financial statements were issued, Forms 5500 were not available for the plan year ending in 2013.
Profit Sharing
Substantially all employees participated in profit sharing plans, which depending on the workgroup, pay from 5% to 20%, of total pre-tax earnings, excluding special items and share-based compensation expense, to eligible employees when pre-tax profit, excluding special items, profit sharing expense and share-based compensation program expense, exceeds $10 million. Eligible U.S. co-workers in each participating work group received a profit sharing payout using a formula based on the ratio of each qualified co-worker’s annual eligible earnings to the eligible earnings of all qualified co-workers in all domestic workgroups. The international profit sharing plan paid eligible non-U.S. co-workers the same percentage of eligible pay that is calculated under the U.S. profit sharing plan for management and administrative employees. Profit sharing expense is recorded as a component of salaries and related costs in the consolidated statements of operations.
The Company recorded profit sharing and related payroll tax expense of $190 million, $119 million and $265 million in 2013, 2012 and 2011, respectively. Profit sharing expense is recorded as a component of salaries and related costs in the consolidated statements of operations.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Measurements	'
	NOTE 9 - FAIR VALUE MEASUREMENTS
	Fair Value Information. Accounting standards require us to use valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are prioritized as follows:
	Level 1	Unadjusted quoted prices in active markets for assets or liabilities identical to those to be reported at fair value
	Level 2	Other inputs that are observable directly or indirectly, such as quoted prices for similar assets or liabilities or market-corroborated inputs
	Level 3	Unobservable inputs for which there is little or no market data and which require us to develop our own assumptions about how market participants would price the assets or liabilities
	The table below presents disclosures about the fair value of financial assets and financial liabilities measured at fair value on a recurring basis in the Company’s financial statements as of December 31 (in millions):
		2013										2012
		Total			Level 1			Level 2		Level 3		Total		Level 1		Level 2		Level 3
		UAL
	Cash and cash equivalents	$	3,220		$	3,220		$	—	$	—	$	4,770	$	4,770	$	—	$	—
	Short-term investments:
	Asset-backed securities		694			—			694		—		715		—		715		—
	Corporate debt		685			—			685		—		537		—		537		—
	Certificates of deposit placed through an account registry service (“CDARS”)		301			—			301		—		367		—		367		—
	Auction rate securities		105			—			—		105		116		—		—		116
	U.S. government and agency notes		38			—			38		—		12		—		12		—
	Other fixed income securities		78			—			78		—		26		—		26		—
	Enhanced equipment trust certificates (“EETC”)		61			—			—		61		63		—		—		63
	Fuel derivatives, net		104			—			104		—		46		—		46		—
	Foreign currency derivatives		1			—			1		—		—		—		—		—
	Restricted cash		395			395			—		—		447		447		—		—
		United
	Cash and cash equivalents	$	3,214		$	3,214		$	—	$	—	$	4,765	$	4,765	$	—	$	—
	Short-term investments:
	Asset-backed securities		694			—			694		—		715		—		715		—
	Corporate debt		685			—			685		—		537		—		537		—
	CDARS		301			—			301		—		367		—		367		—
	Auction rate securities		105			—			—		105		116		—		—		116
	U.S. government and agency notes		38			—			38		—		12		—		12		—
	Other fixed income securities		78			—			78		—		26		—		26		—
	EETC		61			—			—		61		63		—		—		63
	Fuel derivatives, net		104			—			104		—		46		—		46		—
	Foreign currency derivatives		1			—			1		—		—		—		—		—
	Restricted cash		395			395			—		—		447		447		—		—
	Convertible debt derivative asset		480			—			—		480		268		—		—		268
	Convertible debt option liability		-270			—			—		-270		-128		—		—		-128
	Available-for-sale investment maturities - The short-term investments and EETC securities shown in the table above are classified as available-for-sale. As of December 31, 2013, asset-backed securities have remaining maturities of less than one year to approximately 41 years, corporate debt securities have remaining maturities of less than one year to approximately 22 years, CDARS have maturities of less than one year, and auction rate securities have remaining maturities of approximately 19 to 33 years. U.S. government and other securities have maturities of less than one year to approximately five years. The EETC securities have various maturities with the final maturity in 2019.
	The tables below present disclosures about the activity for “Level 3” financial assets and financial liabilities for the year ended December 31 (in millions):
		2013										2012
		UAL and United						United				UAL and United				United
		Student			EETC			Convertible		Convertible		Student		EETC		Convertible		Convertible
		Loan-Related						Debt		Debt		Loan-Related				Debt		Debt
		Auction Rate						Supplemental		Conversion		Auction Rate				Supplemental		Conversion
		Securities						Derivative		Option		Securities				Derivative		Option
								Asset		Liability						Asset		Liability
	Balance at January 1	$	116		$	63		$	268	$	-128	$	113	$	60	$	193	$	-95
	Purchases, (sales), issuances and settlements (net)		-19			-4			—		—		—		-5		—		—
	Gains and (losses):
	Reported in earnings:
	Realized		3			—			—		—		—		—		—		—
	Unrealized		1			—			212		-142		1		—		75		-33
	Reported in other comprehensive income (loss)		4			2			—		—		2		8		—		—
	Balance at December 31	$	105		$	61		$	480	$	-270	$	116	$	63	$	268	$	-128
	United’s debt-related derivatives presented in the tables above relate to (a) supplemental indenture agreements that provide that United’s convertible debt is convertible into shares of UAL common stock upon the terms and conditions specified in the indentures, and (b) the embedded conversion options in United’s convertible debt that are required to be separated and accounted for as though they are free-standing derivatives as a result of the United debt becoming convertible into the common stock of a different reporting entity. The derivatives described above relate to the 6% Convertible Junior Subordinated Debentures due 2030 (the “6% Convertible Debentures”) and the 4.5% Convertible Notes due 2015 (the “4.5% Convertible Notes”). These derivatives are reported in United’s separate financial statements and eliminated in consolidation for UAL.
	Derivative instruments and investments presented in the tables above have the same fair value as their carrying value. The table below presents the carrying values and estimated fair values of financial instruments not presented in the tables above for the years ended December 31 (in millions):
		Fair Value of Debt by Fair Value Hierarchy Level
		2013												2012
		Carrying			Fair Value									Carrying		Fair Value
		Amount												Amount
					Total			Level 1		Level 2		Level 3				Total		Level 1		Level 2		Level 3
	UAL debt	$	11,539		$	12,695		$	—	$	8,829	$	3,866	$	12,252	$	13,419	$	—	$	8,045	$	5,374
	United debt		11,388			12,249			—		8,383		3,866		11,850		12,460		—		7,086		5,374
	Quantitative Information About Level 3 Fair Value Measurements as of December 31, 2013 ($ in millions)
Item	Fair Value at			Valuation Technique		Unobservable Input	Range
	December 31, 2013						(Weighted Average)
Auction rate securities	$	105		Valuation Service / Broker Quotes		Broker quotes (a)	NA
EETC		61		Discounted Cash Flows		Structure credit risk (b)	4% - 5% (4%)
Convertible debt		480		Binomial Lattice Model		Expected volatility (c)	45% - 60% (46%)
derivative asset						Own credit risk (d)	-5%
Convertible debt		(270	)	Binomial Lattice Model		Expected volatility (c)	45% - 60% (47%)
option liability						Own credit risk (d)	-5%
(a) Broker quotes obtained by a third-party valuation service.
(b) Represents the credit risk premium of the EETC structure above the risk-free rate that the Company has determined market participants would use in pricing the instruments.
(c) Represents the range in volatility estimates that the Company has determined market participants would use when pricing the instruments.
(d) Represents the range of Company-specific risk adjustments that the Company has determined market participants would use as a model input.
Valuation Processes - Level 3 Measurements - Depending on the instrument, the Company utilizes broker quotes obtained from third-party valuation services, discounted cash flow methods, or option pricing methods, as indicated above. Valuations using discounted cash flow methods are generally conducted by the Company. Valuations using option pricing models are generally provided to the Company by third-party valuation experts. Each reporting period, the Company reviews the unobservable inputs used by third-party valuation experts for reasonableness utilizing relevant information available to the Company from other sources.
The Company used broker quotes obtained from a valuation service (in replacement of a discounted cash flows method) for valuing auction rate securities. This approach provides the best available information.
Sensitivity Analysis - Level 3 Measurements - Changes in the structure credit risk would be unlikely to cause material changes in the fair value of the EETCs.
The significant unobservable inputs used in the fair value measurement of the United convertible debt derivative assets and liabilities are the expected volatility in UAL common stock and the Company’s own credit risk. Significant increases (decreases) in expected stock volatility would result in a higher (lower) fair value measurement. Significant increases (decreases) in the Company’s own credit risk would result in a lower (higher) fair value measurement. A change in one of the inputs would not necessarily result in a directionally similar change in the other.
Fair value of the Company’s financial instruments was determined as follows:
Description	Fair Value Methodology
Cash and cash equivalents	The carrying amounts approximate fair value because of the short-term maturity of these assets.
Short-term investments and Restricted cash	Fair value is based on (a) the trading prices of the investment or similar instruments, (b) an income approach, which uses valuation techniques to convert future amounts into a single present amount based on current market expectations about those future amounts when observable trading prices are not available, (c) internally-developed models of the expected future cash flows related to the securities, or (d) broker quotes obtained by third-party valuation services.
Fuel derivatives	Derivative contracts are privately negotiated contracts and are not exchange traded. Fair value measurements are estimated with option pricing models that employ observable inputs. Inputs to the valuation models include contractual terms, market prices, yield curves, fuel price curves and measures of volatility, among others.
Foreign currency derivatives	Fair value is determined with a formula utilizing observable inputs. Significant inputs to the valuation models include contractual terms, risk-free interest rates and forward exchange rates.
Debt	Fair values were based on either market prices or the discounted amount of future cash flows using our current incremental rate of borrowing for similar liabilities.
Convertible debt derivative asset and option liability	United used a binomial lattice model to value the conversion options and the supplemental derivative assets. Significant binomial model inputs that are not objectively determinable include volatility and the Company’s credit risk component of the discount rate.

Hedging_Activities

Hedging Activities	12 Months Ended
	Dec. 31, 2013
Hedging Activities	'
	NOTE 10 - HEDGING ACTIVITIES
	Fuel Derivatives
	Aircraft fuel has been the Company’s single largest operating expense for the last several years. The availability and price of aircraft fuel significantly affects the Company’s operations, results of operations, financial position and liquidity. Aircraft fuel prices can fluctuate based on a multitude of factors including market expectations of supply and demand balance, inventory levels, geopolitical events, economic growth expectations, fiscal/monetary policies and financial investment flows. To protect against increases in the prices of aircraft fuel, the Company routinely hedges a portion of its future fuel requirements. As of December 31, 2013, the Company had hedged approximately 24% and 8% of its projected fuel requirements (951 million and 309 million gallons, respectively) for 2014 and 2015, respectively, with commonly used financial hedge instruments based on aircraft fuel or closely related commodities, such as diesel fuel and crude oil. The Company does not enter into derivative instruments for non-risk management purposes.
	Accounting pronouncements pertaining to derivative instruments and hedging are complex with stringent requirements, including documentation of hedging strategy, statistical analysis to qualify a commodity for hedge accounting both on a historical and a prospective basis, and strict contemporaneous documentation that is required at the time each hedge is designated as a cash flow hedge. As required, the Company assesses the effectiveness of each of its individual hedges on a quarterly basis. The Company also examines the effectiveness of its entire hedging program on a quarterly basis utilizing statistical analysis. This analysis involves utilizing regression and other statistical analyses that compare changes in the price of aircraft fuel to changes in the prices of the commodities used for hedging purposes.
	Upon proper qualification, the Company accounts for certain fuel derivative instruments as cash flow hedges. All derivatives designated as hedges that meet certain requirements are granted hedge accounting treatment. The types of instruments the Company utilizes that qualify for special hedge accounting treatment typically include swaps, call options, collars (which consist of a purchased call option and a sold put option) and four-way collars (a collar with a higher strike sold call option and a lower strike purchased put option). Generally, utilizing hedge accounting, all periodic changes in fair value of the derivatives designated as hedges that are considered to be effective are recorded in AOCI until the underlying fuel is consumed and recorded in fuel expense. The Company is exposed to the risk that its hedges may not be effective in offsetting changes in the cost of fuel and that its hedges may not continue to qualify for hedge accounting. Hedge ineffectiveness results when the change in the fair value of the derivative instrument exceeds the change in the value of the Company’s expected future cash outlay to purchase and consume fuel. To the extent that the periodic changes in the fair value of the derivatives are not effective, that ineffectiveness is classified as Nonoperating income (expense): Miscellaneous, net in the statements of consolidated operations.
	The Company also utilizes certain derivative instruments that are economic hedges but do not qualify for hedge accounting under U.S. GAAP. As with derivatives that qualify for hedge accounting, the purpose of these economic hedges is to mitigate the adverse financial impact of potential increases in the price of fuel. Currently, the only such economic hedges in the Company’s hedging portfolio are three-way collars (a collar with a higher strike sold call option). The Company records changes in the fair value of three-way collars to Nonoperating income (expense): Miscellaneous, net in the statements of consolidated operations.
	If the Company terminates a derivative prior to its contractual settlement date, then the cumulative gain or loss recognized in AOCI at the termination date remains in AOCI until the forecasted transaction occurs. In a situation where it becomes probable that a hedged forecasted transaction will not occur, any gains and/or losses that have been recorded to AOCI would be required to be immediately reclassified into earnings. All cash flows associated with purchasing and settling derivatives are classified as operating cash flows in the statements of consolidated cash flows.
	The Company records each derivative instrument as a derivative asset or liability (on a gross basis) in its consolidated balance sheets, and, accordingly, records any related collateral on a gross basis. The table below presents the fair value amounts of fuel derivative assets and liabilities and the location of amounts recognized in the Company’s financial statements.
	At December 31, the Company’s derivatives were reported in its consolidated balance sheets as follows (in millions):
	Classification	Balance Sheet Location		2013				2012
	Derivatives designated as cash flow hedges
	Assets:
	Fuel contracts due within one year	Receivables		$	19			$	7
	Fuel contracts with maturities greater than one year	Other assets: Other, net			6				—
	Total assets			$	25			$	7
	Liabilities:
	Fuel contracts due within one year	Current liabilities: Other		$	—			$	2
	Derivatives not designated for hedge accounting
	Assets:
	Fuel contracts due within one year	Receivables		$	70			$	44
	Fuel contracts with maturities greater than one year	Other assets: Other, net			9				—
	Total assets			$	79			$	44
	Liabilities:
	Fuel contracts due within one year	Current liabilities: Other		$	—			$	2
	Fuel contracts with maturities greater than one year	Other liabilities and deferred credits: Other			—				1
	Total liabilities			$	—			$	3
	Total derivatives
	Assets:
	Fuel contracts due within one year	Receivables		$	89			$	51
	Fuel contracts with maturities greater than one year	Other assets: Other, net			15				—
	Total assets			$	104			$	51
	Liabilities:
	Fuel contracts due within one year	Current liabilities: Other		$	—			$	4
	Fuel contracts with maturities greater than one year	Other liabilities and deferred credits: Other			—				1
	Total liabilities			$	—			$	5
	Offsetting Assets and Liabilities
	We have master trading agreements with all of our fuel hedging counterparties that allow us to net our fuel hedge derivative positions. We have elected not to net the fair value positions recorded on our consolidated balance sheets. The following table shows the potential net fair value positions had we elected to offset. The table reflects offset at the counterparty level (in millions):
		Receivables				Other assets:				Hedge
						Other, net				Derivatives,
										Net
	2013	$	89			$	15			$	104
	2012		46				—				46
	The following tables present the fuel hedge gains (losses) recognized during the periods presented and their classification in the financial statements (in millions):
	Derivatives designated as cash flow hedges
		Amount of Gain (Loss)								Gain (Loss)				Amount of Gain (Loss)
		Recognized								Reclassified from				Recognized in
		in AOCI on Derivatives								AOCI into Income				Nonoperating income
		(Effective Portion)								(Fuel Expense)				(expense):  Miscellaneous, net
										(Effective Portion)				(Ineffective Portion)
		2013				2012				2013		2012		2013		2012
	Fuel contracts	$	39			$	-51			$	18	$	-141	$	5	$	-1
	Derivatives not designated for hedge accounting
		Amount of Gain Recognized
		in Nonoperating income  (expense):
		Miscellaneous, net
		2013				2012				2011
	Fuel contracts	$	79			$	38			$	—
	Derivative Credit Risk and Fair Value
	The Company is exposed to credit losses in the event of nonperformance by counterparties to its derivative instruments. While the Company records derivative instruments on a gross basis, the Company monitors its net derivative position with each counterparty to monitor credit risk. Based on the fair value of our fuel derivative instruments, our counterparties may require us to post collateral when the price of the underlying commodity decreases, and we may require our counterparties to provide us with collateral when the price of the underlying commodity increases. The following table presents information related to the Company’s derivative credit risk as of December 31 (in millions):
		2013				2012
	Net derivative assets with counterparties	$	104			$	46
	Collateral held by the Company (classified as an other current liability)		—				—
	Potential loss related to the failure of the Company’s counterparties to perform		104				46
The Company considers counterparty credit risk in determining its exposure and the fair value of its financial instruments, and generally monitors and limits its exposure to any single counterparty. The Company considers credit risk to have a minimal impact on fair value because cash collateral is provided by the Company’s hedging counterparties periodically based on current market exposure and the credit-worthiness of the counterparties.

Debt

Debt	12 Months Ended
	Dec. 31, 2013
Debt	'
	NOTE 11 - DEBT
	(In millions)	At December 31,
		2013				2012
	United:
	Secured
	Notes payable, fixed interest rates of 4.00% to 12.00% (weighted average rate of 6.50% as of December 31, 2013), payable through 2025	$	6,279			$	5,943
	Notes payable, floating interest rates of the London Interbank Offered Rate (“LIBOR”) plus 0.20% to 5.46%, payable through 2025		1,243				1,668
	Term loan, LIBOR subject to a 1% floor, plus 3%, or alternative rate based on certain market rates plus 2%, due 2019		893				—
	Amended credit facility, LIBOR plus 2.0%, due 2014		—				1,201
	6.75% senior secured notes due 2015		800				800
	9.875% senior secured notes and 12% second lien due 2013		—				600
	Unsecured
	4.5% senior limited subordination convertible notes due 2021		156				156
	6% notes due 2026 to 2028		652				652
	6% senior notes due 2020		300				—
	6% convertible junior subordinated debentures due 2030		248				248
	6.375% senior notes due 2018		300				—
	8% notes due 2024		400				400
	4.5% convertible notes due 2015		230				230
	Other		103				161
			11,604				12,059
	Less: unamortized debt discount		-169				-152
	Less: current portion of long-term debt—United		-1,368				-1,812
	Long-term debt, net—United (a)	$	10,067			$	10,095
	UAL:
	6% convertible senior notes due 2029	$	104			$	345
	Long-term debt, net—UAL	$	10,171			$	10,440
	(a) As further described below under “Convertible Debt Securities and Derivatives,” there is a basis difference between UAL and United debt values, because we were required to apply different accounting methodologies. The United debt presented above does not agree to United’s balance sheet by the amount of this adjustment.
	The table below presents the Company’s contractual principal payments at December 31, 2013 under then-outstanding long-term debt agreements in each of the next five calendar years (in millions):
		UAL				United
	2014	$	1,368			$	1,368
	2015		2,072				2,072
	2016		1,051				1,051
	2017		614				614
	2018		1,135				1,135
	After 2018		5,468				5,364
		$	11,708			$	11,604
	As of December 31, 2013, a substantial portion of the Company’s assets, principally aircraft, spare engines, aircraft spare parts, route authorities and certain other intangible assets, were pledged under various loan and other agreements. As of December 31, 2013, UAL and United were in compliance with their respective debt covenants. Continued compliance depends on many factors, some of which are beyond the Company’s control, including the overall industry revenue environment and the level of fuel costs.
	Unsecured 6.375% Senior Notes. In May 2013, UAL issued $300 million aggregate principal amount of 6.375% Senior Notes due June 1, 2018. The notes are fully and unconditionally guaranteed and recorded by United on its balance sheet as debt. The indenture for the 6.375% Senior Notes requires UAL to offer to repurchase the notes for cash if certain changes of control of UAL occur at a purchase price equal to 101% of the aggregate principal amount of notes repurchased plus accrued and unpaid interest.
	Unsecured 6% Senior Notes. In November 2013, UAL issued $300 million aggregate principal amount of 6% Senior Notes due December 1, 2020. The notes are fully and unconditionally guaranteed and recorded by United on its balance sheet as debt. The indenture for the 6% Senior Notes includes the same change of control covenant as the indenture for the 6.375% Senior Notes.
	6% Convertible Senior Notes. The 6% Convertible Senior Notes due 2029 (the “UAL 6% Convertible Senior Notes”) may be converted by holders into shares of UAL’s common stock at a conversion price of approximately $8.69 per share. UAL does not have the option to pay the conversion price in cash upon a noteholder’s conversion; however, UAL may redeem for cash all or part of the UAL 6% Convertible Senior Notes on or after October 15, 2014. In addition, holders of the UAL 6% Convertible Senior Notes have the right to require UAL to repurchase all or a portion of their notes on each of October 15, 2014, October 15, 2019 and October 15, 2024 or if certain changes of control of UAL occur, payable by UAL in cash, shares of UAL common stock or a combination thereof, at UAL’s option.
	During 2013, UAL issued approximately 28 million shares of UAL common stock pursuant to agreements that UAL entered into with certain of its securityholders in exchange for approximately $240 million in aggregate principal amount of UAL’s outstanding 6% Convertible Senior Notes held by such securityholders. The Company retired the 6% Convertible Senior Notes acquired in the exchange. As of December 31, 2013, the outstanding balance is approximately $104 million. In February 2014, UAL issued 3,582,640 additional shares of UAL common stock pursuant to agreements that UAL entered into with certain of its securityholders of UAL’s 6% Convertible Senior Notes due 2029 in exchange for $31,126,000 in aggregate principal amount.
	4.5% Senior Limited Subordination Convertible Notes. The 4.5% Senior Limited Subordination Convertible Notes due 2021 (the “4.5% Notes”) may be converted by holders into shares of UAL’s common stock at a conversion price of approximately $32.64 per share. In June 2011, UAL repurchased at par value approximately $570 million of the $726 million outstanding principal amount of its 4.5% Notes due 2021 with cash after notes were put to UAL by the noteholders. On January 10, 2014, UAL called all of the 4.5% Notes that remained outstanding for redemption on February 10, 2014. In January and February 2014, holders of substantially all of the remaining $156 million outstanding principal amount of the 4.5% Notes exercised their right to convert such notes into shares of UAL common stock at a conversion rate of 30.6419 shares of UAL common stock per $1,000 principal amount of 4.5% Notes. UAL issued approximately five million shares of UAL common stock in exchange for the 4.5% Notes.
	8% Notes Due 2024. UAL redeemed at par value all $400 million aggregate principal amount of the 8% Notes due 2024 on January 17, 2014. The 8% Notes due 2024 were recorded in current liabilities as of December 31, 2013.
	2013 Credit and Guaranty Agreement. On March 27, 2013, United and UAL entered into the Credit and Guaranty Agreement (the “Credit Agreement”) as the borrower and guarantor, respectively. The Credit Agreement consists of a $900 million term loan due April 1, 2019 and a $1.0 billion revolving credit facility available for drawing until April 1, 2018. As of December 31, 2013, United had its entire commitment capacity of $1.0 billion available under the revolving credit facility.
	Borrowings under the Credit Agreement bear interest at a variable rate equal to LIBOR, subject to a 1% floor, plus a margin of 3.0% per annum, or another rate based on certain market interest rates, plus a margin of 2.0% per annum. The principal amount of the term loan must be repaid in consecutive quarterly installments of 0.25% of the original principal amount thereof, commencing on June 30, 2013, with any unpaid balance due on April 1, 2019. United may prepay all or a portion of the loan from time to time, at par plus accrued and unpaid interest. United pays a commitment fee equal to 0.75% per-annum on the undrawn amount available under the revolving credit facility.
	The Credit Agreement requires United to repay the term loan and any other outstanding borrowings under the Credit Agreement at par plus accrued and unpaid interest if certain changes of control of UAL occur.
	United Amended Credit Facility. On March 27, 2013, the Company used $900 million from the Credit Agreement, together with approximately $300 million of cash to retire the entire principal balance of a $1.2 billion term loan due 2014 that was outstanding under United’s Amended and Restated Revolving Credit, Term Loan and Guaranty Agreement, dated as of February 2, 2007 (the “Amended Credit Facility”). The Amended Credit Facility was terminated concurrently with the repayment of the term loan.
	As of December 31, 2013, United had cash collateralized $61 million of letters of credit, most of which had previously been issued under the Credit Agreement. United also had $398 million of performance bonds and letters of credit relating to various real estate, customs and aircraft financing obligations at December 31, 2013. Most of the letters of credit have evergreen clauses and are expected to be renewed on an annual basis and the performance bonds have expiration dates through 2018.
	EETCs. United has $6.0 billion principal amount of equipment notes outstanding issued under EETC financings included in notes payable in the table of outstanding debt above. Generally, the structure of all of these EETC financings consist of pass-through trusts created by United to issue pass-through certificates, which represent fractional undivided interests in the respective pass-through trusts and are not obligations of United. The proceeds of the issuance of the pass-through certificates are used to purchase equipment notes which are issued by United and secured by its aircraft. The payment obligations under the equipment notes are those of United. Proceeds received from the sale of pass-through certificates are initially held by a depositary in escrow for the benefit of the certificate holders until United issues equipment notes to the trust, which purchases such notes with a portion of the escrowed funds. These escrowed funds are not guaranteed by United and are not reported as debt on our consolidated balance sheet because the proceeds held by the depositary are not United’s assets.
	In August 2013, December 2012 and October 2012, United created separate EETC pass-through trusts, each of which issued pass-through certificates. The proceeds of the issuance of the pass-through certificates are used to purchase equipment notes issued by United and secured by its aircraft. The Company records the debt obligation upon issuance of the equipment notes rather than upon the initial issuance of the pass-through certificates. United has received all of the proceeds from the 2012 EETCs. United expects to receive all proceeds from the August 2013 pass-through trusts by the end of 2014. Certain details of the pass-through trusts are as follows (in millions, except interest rate):
	EETC Date	Class		Principal				Final	Stated		Total debt		Proceeds		Remaining
								expected	interest		recorded		received from		proceeds from
								distribution	rate		as of December 31,		issuance of		issuance of debt
								date			2013		debt during		to be received
													2013		in future
															periods
	Aug-13	A		$	720			August 2025		4.30%	$	153	$	153	$	567
	Aug-13	B			209			Aug-21		5.38%		44		44		165
	Dec-12	C			425			Apr-18		6.13%		425		147		—
	Oct-12	A			712			October 2024		4.00%		712		465		—
	Oct-12	B			132			Oct-20		5.50%		132		86		—
				$	2,198						$	1,466	$	895	$	732
6.75% Notes. In August 2010, United issued $800 million aggregate principal amount of 6.75% Senior Secured Notes due 2015 (the “Senior Notes”). United may redeem all or a portion of the Senior Notes at any time on or after September 15, 2012 at specified redemption prices. If United sells certain of its assets or if it experiences specific kinds of a change in control, United will be required to offer to repurchase the notes. United’s obligations under the notes are unconditionally guaranteed by certain of its subsidiaries.
4.5% Convertible Notes. The 4.5% Convertible Notes may be converted by holders into shares of UAL common stock at a conversion price of approximately $18.93 per share. The Company does not have the option to pay the conversion price in cash; however, holders of the notes may require the Company to repurchase all or a portion of the notes for cash at par plus any accrued and unpaid interest if certain changes in control of the Company occur.
6% Convertible Junior Subordinated Debentures. Continental Airlines Finance Trust II, a Delaware statutory business trust (the “Trust”) of which United owns all the common trust securities, has outstanding five million 6% convertible preferred securities, called Term Income Deferrable Equity Securities (the “TIDES”). The TIDES have a liquidation value of $50 per preferred security and are convertible at any time at the option of the holder into shares of UAL common stock at a conversion rate of $57.14 per share of common stock (equivalent to approximately 0.875 of a share of UAL common stock for each preferred security). Distributions on the preferred securities are payable by the Trust at an annual rate of 6% of the liquidation value of $50 per preferred security.
The sole assets of the Trust are the 6% Convertible Debentures with an aggregate principal amount of $248 million as of December 31, 2012 mature on November 15, 2030. The 6% Convertible Debentures are redeemable, in whole or in part, on or after November 20, 2003 at designated redemption prices. If we redeem the 6% Convertible Debentures, the Trust must redeem the TIDES on a pro rata basis having an aggregate liquidation value equal to the aggregate principal amount of the 6% Convertible Debentures redeemed. Otherwise, the TIDES will be redeemed upon maturity of the 6% Convertible Debentures, unless previously converted.
Taking into consideration the obligations under (i) the preferred securities guarantee relating to the TIDES, (ii) the indenture relating to the 6% Convertible Debentures to pay all debt and obligations and all costs and expenses of the Trust (other than U.S. withholding taxes) and (iii) the indenture, the declaration of trust relating to the TIDES and the 6% Convertible Debentures, United has fully and unconditionally guaranteed payment of (i) the distributions on the TIDES, (ii) the amount payable upon redemption of the TIDES and (iii) the liquidation amount of the TIDES.
The Trust is a subsidiary of United, and the TIDES are mandatorily redeemable preferred securities with a liquidation value of $248 million. The Trust is a variable interest entity (“VIE”) because the Company has a limited ability to make decisions about its activities. However, the Company is not the primary beneficiary of the Trust. Therefore, the Trust and the mandatorily redeemable preferred securities issued by the Trust are not reported in the Company’s balance sheets. Instead, the Company reports its 6% convertible junior subordinated debentures held by the Trust as long-term debt and interest on these debentures is recorded as interest expense for all periods presented in the accompanying financial statements.
Convertible Debt Securities and Derivatives. Following the Merger, Continental and the trustees for the 4.5% Convertible Notes, 5% Convertible Notes due 2023 and 6% Convertible Debentures entered into supplemental indenture agreements to make United’s convertible debt, which was previously convertible into shares of Continental common stock, convertible into shares of UAL common stock. For purposes of the United separate-entity reporting, as a result of this debt, which is now United debt, becoming convertible into the stock of a non-consolidated entity, the embedded conversion options in United’s convertible debt are required to be separated and accounted for as though they are free-standing derivatives. As a result, the carrying value of United’s debt, net of current maturities, on a separate-entity reporting basis as of December 31, 2013 and December 31, 2012 was $10 billion and $10 billion, respectively, which is $47 million and $57 million, respectively, lower than the consolidated UAL carrying values on those dates.
In addition, UAL’s contractual commitment to provide common stock to satisfy United’s obligation upon conversion of the debt is an embedded call option on UAL common stock that is also required to be separated and accounted for as though it is a free-standing derivative. The fair value of the indenture derivatives on a separate-entity reporting basis as of December 31, 2013 and December 31, 2012 was an asset of $480 million and $268 million, respectively. The fair value of the embedded conversion options as of December 31, 2013 and December 31, 2012, was a liability of $270 million and $128 million, respectively. The initial contribution of the indenture derivatives to United by UAL is accounted for as additional-paid-in-capital in United’s separate-entity financial statements. Changes in fair value of both the indenture derivatives and the embedded conversion options subsequent to October 1, 2010 are recognized currently in nonoperating income (expense).
The collateral, covenants and cross default provisions of the Company’s principal debt instruments that contain such provisions are summarized in the table below:
Debt Instrument	Collateral, Covenants and Cross Default Provisions
Credit Agreement	Secured by certain of United’s international route authorities, specified take-off and landing slots at certain airports and certain other assets.
	The Credit Agreement requires the Company to maintain at least $3.0 billion of unrestricted liquidity at all times, which includes unrestricted cash, short-term investments and any undrawn amounts under any revolving credit facility and to maintain a minimum ratio of appraised value of collateral to the outstanding obligations under the Credit Agreement of 1.67 to 1.0 at all times. The Credit Agreement contains covenants that, among other things, restrict the ability of UAL and its restricted subsidiaries (as defined in the Credit Agreement) to incur additional indebtedness and to pay dividends on or repurchase stock.
	The Credit Agreement contains events of default customary for this type of financing, including a cross default and cross acceleration provision to certain other material indebtedness of the Company.
6% Notes due 2026	The amended and restated indenture for these notes, which are unsecured, contains covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indenture) to incur additional indebtedness and pay dividends on or repurchase stock.
6% Notes due 2028	These covenants cease to be in effect when the indenture covering the 6.375% Senior Notes due 2018 is discharged.
	The indenture contains events of default that are customary for similar financings.
6.375% Senior Notes due 2018	The indentures for these notes, which are unsecured, contain covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indenture) to incur additional indebtedness and pay dividends on or repurchase stock.
6% Senior Notes due 2020	The indentures contain events of default that are customary for similar financings.
6.75% Senior Notes due 2015	Secured by certain of United’s U.S.-Asia and U.S.-London Heathrow routes and related assets, all of the outstanding common stock and other assets of Air Micronesia, Inc. (“AMI”) and Continental Micronesia, Inc. (“CMI”) and substantially all of the other assets of AMI and CMI, including route authorities and related assets.
	The indenture for these notes includes covenants that, among other things, restrict United’s ability to sell assets, incur additional indebtedness, issue preferred stock, make investments and pay dividends on or repurchase stock. In addition, if United fails to maintain a collateral coverage ratio of 1.5 to 1.0, United must pay additional interest on the Senior Notes at the rate of 2% per annum until the collateral coverage ratio equals at least 1.5 to 1.0.
	The indenture for these notes also includes events of default customary for similar financings and a cross default provision if United fails to make payment when due with respect to certain obligations regarding frequent flyer miles purchased by Chase under United’s Co-Brand Agreement.

Advanced_Purchase_of_Miles

Advanced Purchase of Miles	12 Months Ended
	Dec. 31, 2013
Advanced Purchase of Miles	'
	NOTE 12 - ADVANCED PURCHASE OF MILES
	United previously sold frequent flyer miles to Chase which United recorded as Advanced Purchase of Miles. United has the right, but is not required, to repurchase the pre-purchased miles from Chase during the term of the agreement. The balance of pre-purchased miles is eligible to be allocated by Chase to MileagePlus members’ accounts by a maximum of $199 million in 2014, $224 million in 2015, $249 million in 2016 and the remainder in 2017. The Co-Brand Agreement contains termination penalties that may require United to make certain payments and repurchase outstanding pre-purchased miles in cases such as United’s insolvency, bankruptcy or other material breaches. The Company has recorded these amounts as advanced purchase of miles in the liabilities section of the Company’s consolidated balance sheets.
	The obligations of UAL, United and Mileage Plus Holdings, LLC to Chase under the Co-Brand Agreement are joint and several. Certain of United’s obligations under the Co-Brand Agreement in an amount not more than $850 million are secured by a junior lien in all collateral pledged by United under the Credit Agreement. All of United’s obligations under the Co-Brand Agreement are secured by a junior lien in all collateral pledged by United to secure its 6.75% Senior Notes due 2015. United also provides a first priority lien to Chase on its MileagePlus assets to secure certain of its obligations under the Co-Brand Agreement and its obligations under the new combined credit card processing agreement among United, Paymentech, LLC and JPMorgan Chase.

Leases_and_Capacity_Purchase_A

Leases and Capacity Purchase Agreements	12 Months Ended
	Dec. 31, 2013
Leases and Capacity Purchase Agreements	'
	NOTE 13 - LEASES AND CAPACITY PURCHASE AGREEMENTS
	United leases aircraft, airport passenger terminal space, aircraft hangars and related maintenance facilities, cargo terminals, other airport facilities, other commercial real estate, office and computer equipment and vehicles.
	At December 31, 2013, United’s scheduled future minimum lease payments under operating leases having initial or remaining noncancelable lease terms of more than one year, aircraft leases, including aircraft rent under CPAs and capital leases (substantially all of which are for aircraft) were as follows (in millions):
		Capital Leases (a)		Facility and Other		Aircraft Operating
				Operating Leases		Leases (b)
	2014	$	206	$	1,192	$	1,601
	2015		183		987		1,381
	2016		168		864		1,150
	2017		123		831		1,053
	2018		106		710		786
	After 2018		678		6,002		1,819
	Minimum lease payments	$	1,464	$	10,586	$	7,790
	Imputed interest		-594
	Present value of minimum lease payments		870
	Current portion		-117
	Long-term obligations under capital leases	$	753
	(a) As of December 31, 2013, United’s aircraft capital lease minimum payments relate to leases of 47 mainline and 38 regional aircraft as well as to leases of nonaircraft assets. Imputed interest rate ranges are 4.8% to 18.5%.
	(b) The operating lease payments presented above include future payments of $103 million related to 25 nonoperating aircraft as of December 31, 2013.
	Aircraft operating leases have initial terms of six to twenty-six years, with expiration dates ranging from 2014 through 2024. Under the terms of most leases, United has the right to purchase the aircraft at the end of the lease term, in some cases at fair market value, and in others, at fair market value or a percentage of cost. United has facility operating leases that extend to 2041.
	United is the lessee of real property under long-term operating leases at a number of airports where we are also the guarantor of approximately $1.6 billion of underlying debt and interest thereon as of December 31, 2013. These leases are typically with municipalities or other governmental entities, which are excluded from the consolidation requirements concerning VIEs. To the extent United’s leases and related guarantees are with a separate legal entity other than a governmental entity, United is not the primary beneficiary because the lease terms are consistent with market terms at the inception of the lease and the lease does not include a residual value guarantee, fixed-price purchase option, or similar feature.
	In April 2013, United executed an amendment to its Terminal C lease at Newark Liberty International Airport (“Newark Liberty”) that, among other matters, extended the term of the Terminal C lease with respect to concourses C-1 and C-2 at Newark Liberty until 2033. United also committed to invest an additional $150 million in facility upgrades at Newark Liberty to enhance the customer experience and efficiency of the operation.
	In November 2013, United signed a lease amendment with the City of Los Angeles and Los Angeles World Airports (“LAWA”) to its terminal facilities lease at Los Angeles International Airport (“LAX”). The amendment allows United to make approximately $450 million in renovations at LAX over the next four years. United will fund the cost of these renovations and LAWA will acquire the improvements at the end of each designated construction phase through a cash payment at the construction cost. United expects to be considered the owner of the property during and after the construction period for accounting purposes. As a result, the construction project will be included on the Company’s balance sheet as operating property and equipment and with the construction obligation under other liabilities.
	United’s nonaircraft rent expense was approximately $1.3 billion for each of the years ended December 31 2013, 2012, and 2011.
	In addition to nonaircraft rent and aircraft rent, which is separately presented in the consolidated statements of operations, United had aircraft rent related to regional aircraft operating leases, which is included as part of regional capacity purchase expense in United’s consolidated statement of operations, of $428 million, $463 million and $498 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	In connection with UAL Corporation’s and United Air Lines, Inc.’s fresh-start reporting requirements upon their exit from Chapter 11 bankruptcy protection in 2006 and the Company’s acquisition accounting adjustments related to the Merger, lease valuation adjustments for operating leases were initially recorded in the consolidated balance sheet, representing the net present value of the differences between contractual lease rates and the fair market lease rates for similar leased assets at the time. An asset (liability) results when the contractual lease rates are more (less) favorable than market lease terms at the valuation date. The lease valuation adjustment is amortized on a straight-line basis as an increase (decrease) to rent expense over the individual applicable remaining lease terms, resulting in recognition of rent expense as if United had entered into the leases at market rates. The related remaining lease terms are one to 11 years for United. The lease valuation adjustments are classified within other noncurrent liabilities and the net accretion amounts are $173 million, $240 million and $227 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	Regional CPAs
	United has CPAs with certain regional carriers. We purchase all of the capacity from the flights covered by the CPA at a negotiated price. We pay the regional carrier a pre-determined rate, subject to annual inflation adjustments, primarily for block hours flown (the hours from gate departure to gate arrival) and other operating factors and reimburse the regional carrier for various pass-through expenses related to the flights. Under the CPAs, we are responsible for the cost of providing fuel for all flights and for paying aircraft rent for all of the aircraft covered by the CPAs. Generally, the CPAs contain incentive bonus and rebate provisions based upon each regional carrier’s operational performance. United’s CPAs are for 572 regional aircraft, and the CPAs have terms expiring through 2027. Aircraft operated under CPAs include aircraft leased directly from the regional carriers and those leased from third-party lessors and operated by the regional carriers.
	In May 2013, United entered into a CPA with SkyWest Airlines, Inc. (“SkyWest”), a wholly-owned subsidiary of SkyWest, Inc., to operate 40 Embraer S.A. (“Embraer”) EMB175 aircraft under the United Express brand. SkyWest will purchase these 76-seat aircraft with deliveries in 2014 and 2015.
	In April 2013, United agreed to purchase 30 Embraer EMB175 aircraft. In August 2013, United entered into a CPA with Mesa Air Group, Inc. and Mesa Airlines, Inc. (“Mesa”), a wholly-owned subsidiary of Mesa Air Group, Inc., for Mesa to operate these 30 Embraer EMB175 aircraft under the United Express brand.
	Our future commitments under our CPAs are dependent on numerous variables, and are therefore difficult to predict. The most important of these variables is the number of scheduled block hours. Although we are not required to purchase a minimum number of block hours under certain of our CPAs, we have set forth below estimates of our future payments under the CPAs based on our assumptions. United’s estimates of its future payments under all of the CPAs do not include the portion of the underlying obligation for any aircraft leased to ExpressJet or deemed to be leased from other regional carriers and facility rent that are disclosed as part of aircraft and nonaircraft operating leases. For purposes of calculating these estimates, we have assumed (1) the number of block hours flown is based on our anticipated level of flight activity or at any contractual minimum utilization levels if applicable, whichever is higher, (2) that we will reduce the fleet as rapidly as contractually allowed under each CPA, (3) that aircraft utilization, stage length and load factors will remain constant, (4) that each carrier’s operational performance will remain at historic levels and (5) that inflation is projected to be between 1.38% and 2.50% per year. These amounts exclude variable pass-through costs such as fuel and landing fees, among others. Based on these assumptions as of December 31, 2013, our future payments through the end of the terms of our CPAs are presented in the table below (in millions):
	2014	$	1,936
	2015		1,747
	2016		1,532
	2017		1,449
	2018		1,340
	After 2018		3,410
		$	11,414
	It is important to note that the actual amounts we pay to our regional operators under CPAs could differ materially from these estimates. For example, a 10% increase or decrease in scheduled block hours for all of United’s regional operators (whether as a result of changes in average daily utilization or otherwise) in 2014 would result in a corresponding change in annual cash obligations under the CPAs of approximately $159 million (8.2%).

Variable_Interest_Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2013
Variable Interest Entities	'
	NOTE 14 - VARIABLE INTEREST ENTITIES
	Variable interests are contractual, ownership or other monetary interests in an entity that change with fluctuations in the fair value of the entity’s net assets exclusive of variable interests. A VIE can arise from items such as lease agreements, loan arrangements, guarantees or service contracts. An entity is a VIE if (a) the entity lacks sufficient equity or (b) the entity’s equity holders lack power or the obligation and right as equity holders to absorb the entity’s expected losses or to receive its expected residual returns. Therefore, if the equity owners as a group do not have the power to direct the entity’s activities that most significantly impact its economic performance, the entity is a VIE.
	If an entity is determined to be a VIE, the entity must be consolidated by the primary beneficiary. The primary beneficiary is the holder of the variable interests that has the power to direct the activities of a VIE that (i) most significantly impact the VIE’s economic performance and (ii) has the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the VIE. Therefore, the Company must identify which activities most significantly impact the VIE’s economic performance and determine whether it, or another party, has the power to direct those activities.
	The Company’s evaluation of its association with VIEs is described below:
	Aircraft Leases. We are the lessee in a number of operating leases covering the majority of our leased aircraft. The lessors are trusts established specifically to purchase, finance and lease aircraft to us. These leasing entities meet the criteria for VIEs. We are generally not the primary beneficiary of the leasing entities if the lease terms are consistent with market terms at the inception of the lease and do not include a residual value guarantee, fixed-price purchase option or similar feature that obligates us to absorb decreases in value or entitles us to participate in increases in the value of the aircraft. This is the case for many of our operating leases; however, leases of approximately 72 mainline jet aircraft contain a fixed-price purchase option that allow United to purchase the aircraft at predetermined prices on specified dates during the lease term. Additionally, leases covering approximately 256 leased regional jet aircraft contain an option to purchase the aircraft at the end of the lease term at prices that, depending on market conditions, could be below fair value. United has not consolidated the related trusts because, even taking into consideration these purchase options, United is still not the primary beneficiary. United’s maximum exposure under these leases is the remaining lease payments, which are reflected in future lease commitments in Note 13 of this report.
	EETCs. United evaluated whether the pass-through trusts formed for its EETC financings, treated as either debt or aircraft operating leases, are VIEs required to be consolidated by United under applicable accounting guidance, and determined that the pass-through trusts are VIEs. Based on United’s analysis as described below, United determined that it does not have a variable interest in the pass-through trusts.
	The primary risk of the pass-through trusts is credit risk (i.e. the risk that United, the issuer of the equipment notes, may be unable to make its principal and interest payments). The primary purpose of the pass-through trust structure is to enhance the credit worthiness of United’s debt obligation through certain bankruptcy protection provisions, a liquidity facility (in certain of the EETC structures) and improved loan-to-value ratios for more senior debt classes. These credit enhancements lower United’s total borrowing cost. Pass-through trusts are established to receive principal and interest payments on the equipment notes purchased by the pass-through trusts from United and remit these proceeds to the pass-through trusts’ certificate holders.
	United does not invest in or obtain a financial interest in the pass-through trusts. Rather, United has an obligation to make interest and principal payments on its equipment notes held by the pass-through trusts. United did not intend to have any voting or non-voting equity interest in the pass-through trusts or to absorb variability from the pass-through trusts. Based on this analysis, the Company determined that it is not required to consolidate the pass-through trusts.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies	'
	NOTE 15 - COMMITMENTS AND CONTINGENCIES
	Commitments. As of December 31, 2013, United had firm commitments to purchase aircraft from The Boeing Company (“Boeing”), Embraer and Airbus S.A.S. (“Airbus”) presented in the table below:
	Aircraft Type	Number of Firm
		Commitments (a)
	Airbus A350-1000		35
	Boeing 737-900ER		63
	Boeing 737 MAX 9		100
	Boeing 787-8/-9/-10		57
	Embraer EMB175		30
	(a) United also has options and purchase rights for additional aircraft.
	The aircraft listed in the table above are scheduled for delivery from 2014 through 2025.
	The table below summarizes United’s commitments as of December 31, 2013 (including those assigned from UAL), which primarily relate to the acquisition of aircraft and related spare engines, aircraft improvements and include other commitments primarily to acquire information technology services and assets for the years ended December 31 (in billions):
	2014	$	3.0
	2015		2.8
	2016		2.0
	2017		1.5
	2018		2.1
	After 2018		12.5
		$	23.9
	Any incremental firm aircraft orders, including through the exercise of purchase options and purchase rights, will increase the total future capital commitments of the Company.
	As of December 31, 2013, United has arranged for EETC financing of 15 Boeing 737-900ER aircraft and two Boeing 787-8 aircraft, which are scheduled to be delivered from January through June 2014. In addition, United has secured backstop financing commitments from certain of its aircraft manufacturers for a limited number of its future aircraft deliveries, subject to certain customary conditions. However, the Company does not have backstop financing or any financing currently in place for its other firm aircraft orders. Financing will be necessary to satisfy the Company’s capital commitments for its firm order aircraft and other related capital expenditures. The Company can provide no assurance that any financing not already in place for aircraft and spare engine deliveries will be available to the Company on acceptable terms when necessary or at all.
	Legal and Environmental. The Company has certain contingencies resulting from litigation and claims incident to the ordinary course of business. Management believes, after considering a number of factors, including (but not limited to) the information currently available, the views of legal counsel, the nature of contingencies to which the Company is subject and prior experience, that the ultimate disposition of the litigation and claims will not materially affect the Company’s consolidated financial position or results of operations. The Company records liabilities for legal and environmental claims when a loss is probable and reasonably estimable. These amounts are recorded based on the Company’s assessments of the likelihood of their eventual disposition.
	Guarantees and Indemnifications. In the normal course of business, the Company enters into numerous real estate leasing and aircraft financing arrangements that have various guarantees included in the contracts. These guarantees are primarily in the form of indemnities under which the Company typically indemnifies the lessors and any tax/financing parties against tort liabilities that arise out of the use, occupancy, operation or maintenance of the leased premises or financed aircraft. Currently, the Company believes that any future payments required under these guarantees or indemnities would be immaterial, as most tort liabilities and related indemnities are covered by insurance (subject to deductibles). Additionally, certain leased premises such as fueling stations or storage facilities include indemnities of such parties for any environmental liability that may arise out of or relate to the use of the leased premises.
	United is the guarantor of approximately $1.9 billion in aggregate principal amount of tax-exempt special facilities revenue bonds and interest thereon. These bonds, issued by various airport municipalities, are payable solely from rentals paid under long-term agreements with the respective governing bodies. The leasing arrangements associated with $1.6 billion of these obligations are accounted for as operating leases with the associated expense recorded on a straight-line basis resulting in ratable accrual of the lease obligation over the expected lease term. These tax-exempt special facilities revenue bonds are included in our lease commitments disclosed in Note 13 of this report. The leasing arrangements associated with $267 million of these obligations are accounted for as capital leases. All these bonds are due between 2015 and 2038.
	In United’s financing transactions that include loans, United typically agrees to reimburse lenders for any reduced returns with respect to the loans due to any change in capital requirements and, in the case of loans in which the interest rate is based on LIBOR, for certain other increased costs that the lenders incur in carrying these loans as a result of any change in law, subject in most cases to obligations of the lenders to take certain limited steps to mitigate the requirement for, or the amount of, such increased costs. At December 31, 2013, the Company had $2.1 billion of floating rate debt and $286 million of fixed rate debt, with remaining terms of up to twelve years, that are subject to these increased cost provisions. In several financing transactions involving loans or leases from non-U.S. entities, with remaining terms of up to twelve years and an aggregate balance of $2.3 billion, the Company bears the risk of any change in tax laws that would subject loan or lease payments thereunder to non-U.S. entities to withholding taxes, subject to customary exclusions.
	Fuel Consortia. United participates in numerous fuel consortia with other air carriers at major airports to reduce the costs of fuel distribution and storage. Interline agreements govern the rights and responsibilities of the consortia members and provide for the allocation of the overall costs to operate the consortia based on usage. The consortia (and in limited cases, the participating carriers) have entered into long-term agreements to lease certain airport fuel storage and distribution facilities that are typically financed through tax-exempt bonds (either special facilities lease revenue bonds or general airport revenue bonds), issued by various local municipalities. In general, each consortium lease agreement requires the consortium to make lease payments in amounts sufficient to pay the maturing principal and interest payments on the bonds. As of December 31, 2013, approximately $1.2 billion principal amount of such bonds were secured by significant fuel facility leases in which United participates, as to which United and each of the signatory airlines has provided indirect guarantees of the debt. As of December 31, 2013, the Company’s contingent exposure was approximately $250 million principal amount of such bonds based on its recent consortia participation. The Company’s contingent exposure could increase if the participation of other air carriers decreases. The guarantees will expire when the tax-exempt bonds are paid in full, which ranges from 2014 to 2041. The Company did not record a liability at the time these indirect guarantees were made.
	Credit Card Processing Agreements. United has agreements with financial institutions that process customer credit card transactions for the sale of air travel and other services. Under certain of United’s credit card processing agreements, the financial institutions either require, or under certain circumstances have the right to require, that United maintains a reserve equal to a portion of advance ticket sales that has been processed by that financial institution, but for which United has not yet provided the air transportation. Such financial institutions may require additional cash or other collateral reserves to be established or additional withholding of payments related to receivables collected if United does not maintain certain minimum levels of unrestricted cash, cash equivalents and short term investments. United’s current level of unrestricted cash, cash equivalents and short term investments is substantially in excess of these minimum levels.
	Labor Negotiations. As of December 31, 2013, United, including its subsidiaries, had approximately 87,000 employees. Approximately 80% of United’s employees were represented by various U.S. labor organizations as of December 31, 2013.
	In the fourth quarter 2013, the Company announced that the fleet service, passenger service and storekeeper work groups at its United, CMI and MileagePlus subsidiaries ratified new joint labor agreements. We are in the process of negotiating amended collective bargaining agreements with our remaining employee groups without joint collective bargaining agreements, including our technicians, flight attendants and dispatchers.

Statement_of_Consolidated_Cash

Statement of Consolidated Cash Flows - Supplemental Disclosures	12 Months Ended
	Dec. 31, 2013
Statement of Consolidated Cash Flows - Supplemental Disclosures	'
	NOTE 16 - STATEMENT OF CONSOLIDATED CASH FLOWS - SUPPLEMENTAL DISCLOSURES
	Supplemental disclosures of cash flow information and non-cash investing and financing activities for the years ended December 31 are as follows (in millions):
	2013	UAL		United
	Cash paid (refunded) during the period for:
	Interest (net of amounts capitalized)	$	752	$	752
	Income taxes		-20		-15
	Non-cash transactions:
	Net property and equipment acquired through issuance of debt	$	229	$	229
	Airport construction financing		40		40
	Exchanges of certain 6% convertible senior notes for common stock		240		—
	2012
	Cash paid during the period for:
	Interest (net of amounts capitalized)	$	766	$	766
	Income taxes		2		4
	Non-cash transactions:
	Net property and equipment acquired through issuance of debt	$	544	$	544
	8% Contingent Senior Unsecured Notes and 6% Senior Notes, net of discount		357		357
	Special facility payment financing		101		101
	Airport construction financing		50		50
	2011
	Cash paid during the period for:
	Interest (net of amounts capitalized)	$	855	$	855
	Income taxes		10		2
	Non-cash transactions:
	Net property and equipment acquired through issuance of debt	$	130	$	130
	8% Contingent Senior Unsecured Notes, net of discount		88		88
	Interest paid in kind on 6% Senior Notes		37		37

IntegrationRelated_Costs_and_S

Integration-Related Costs and Special Items	12 Months Ended
	Dec. 31, 2013
Integration-Related Costs and Special Items	'
	NOTE 17 - INTEGRATION-RELATED COSTS AND SPECIAL ITEMS
	Integration-related costs and special items classified as special charges in the statements of consolidated operations consisted of the following for the years ended December 31 (in millions):
		2013			2012			2011
	Integration-related costs	$	205		$	739		$	517
	Labor agreement costs		127			475			—
	Severance and benefits		105			125			—
	Asset impairments		33			30			4
	Termination of maintenance service contract		—			—			58
	Additional costs associated with the temporarily grounded Boeing 787 aircraft		18			—			—
	(Gains) losses on sale of assets and other special charges, net		32			-46			13
	Total	$	520		$	1,323		$	592
	Integration-related costs
	Integration-related costs incurred during 2013 and 2012 included compensation costs related to systems integration and training, branding activities, write-off or acceleration depreciation on systems and facilities that are either no longer used or planned to be used for significantly shorter periods, as well as relocation for employees and severance primarily associated with administrative headcount reductions. In 2011, these costs also included costs to terminate certain service contracts, costs to write-off system assets, payments to third-party consultants assisting with integration planning and organization design and compensation costs related to the systems integration. In addition, the Company recorded a liability of $88 million related to the fair value of UAL’s obligation to issue to the PBGC $125 million aggregate principal amount of 8% Contingent Senior Notes during 2011. This was classified as an integration-related cost since the financial results of the Company, excluding Continental’s results, would not have resulted in a triggering event under the 8% Contingent Senior Notes indenture.
	On December 31, 2012, UAL and United Air Lines, Inc. entered into an agreement with the PBGC that reduced the aggregate amount of 8% Contingent Senior Notes to be issued by UAL, and eliminated the contingent nature of such obligation by replacing the $188 million principal amount of 8% Contingent Senior Notes incurred as of December 31, 2012 and the obligation to issue any additional 8% Contingent Senior Notes with $400 million principal amount of new 8% Notes due 2024 (the “New 8% Notes”). In addition, UAL agreed to replace the $652 million principal amount outstanding of 6% Senior Notes due 2031 with $326 million principal amount of new 6% Notes due 2026 and $326 million principal amount of 6% Notes due 2028 (collectively, the “New 6% Notes” and together with the New 8% Notes, the “New PBGC Notes”). The Company did not receive any cash proceeds in connection with the issuance of the New PBGC Notes. The Company is accounting for this agreement as a debt extinguishment, resulting in a charge of $309 million in 2012 that represents the fair value of $212 million of New 8% Notes that it agreed to issue and the change in the fair value of the New 6% Notes and the $188 million of New 8% Notes versus their previous carrying values. The Company classified the expense as a component of special charges because the note restructuring would not have occurred if it were not for the Merger.
	Labor agreement costs
	In October 2013, fleet service, passenger service and storekeeper employees represented by the IAM ratified a joint collective bargaining agreement with the Company. The Company recorded a $127 million special charge for lump sum payments made in conjunction with the ratification. The lump sum payments are not in lieu of future pay increases. The Company completed substantially all cash payments in 2013.
	In December 2012, the pilots represented by the Air Line Pilots Association, International ratified a new joint collective bargaining agreement with the Company. The Company recorded $475 million of expense associated with lump sum cash payments that would be made in conjunction with the ratification of the contract and the completion of the integrated pilot seniority list. This charge also includes $80 million associated with changes to existing pilot disability plans negotiated in connection with the agreement. The lump sum payments are not in lieu of future pay increases. The Company completed substantially all cash payments in 2013.
	Severance and benefits
	During 2013, the Company offered a voluntary retirement program for its fleet service, passenger service, storekeeper and pilot workgroups. Approximately 1,200 employees volunteered under the program during the fourth quarter of 2013 and United recorded approximately $64 million of costs for the programs. The Company also offered voluntary leave of absence programs which allows for continued medical coverage for flight attendants who volunteered during the leave of absence period, resulting in a charge of approximately $26 million. The remaining $15 million of severance and benefit costs is related to involuntary severance programs associated with flight attendants and other workgroups.
	During 2012, the Company recorded $125 million of severance and benefits associated with various voluntary retirement and leave of absence programs for its various employee groups. During the first quarter of 2012, approximately 400 mechanics offered to retire early in exchange for a cash severance payment that was based on the number of years of service each employee had accumulated. The expense for this voluntary program was approximately $32 million. The Company also offered a voluntary leave of absence program that approximately 1,800 flight attendants accepted, which allows for continued medical coverage during the leave of absence period. The expense for this voluntary program was approximately $17 million. During the second quarter of 2012, as part of the recently amended collective bargaining agreement with the Association of Flight Attendants, the Company offered a voluntary program for flight attendants to retire early in exchange for a cash severance payment. The payments are dependent on the number of years of service each employee has accumulated. Approximately 1,300 flight attendants accepted this program and the expense for this voluntary program is approximately $76 million.
	Asset impairments
	During 2013 and 2012, the Company recorded impairment charges of $1 million and $30 million, respectively, on certain intangible assets including a route to Manila and European take-off and landing slots, respectively, in order to reflect the estimated fair value of these assets as part of its annual impairment test of indefinite-lived intangible assets.
	In addition, during 2013, the Company recorded $32 million of impairment charges of its flight equipment held for disposal associated with its Boeing 737-300 and 737-500 fleets.
	Temporary grounding of Boeing 787 aircraft
	During 2013, the Company recorded $18 million associated with the temporary grounding of its Boeing 787 aircraft. The charges are comprised of aircraft depreciation expense and dedicated personnel costs that the Company incurred while the aircraft were grounded. The aircraft returned to service in May 2013.
	Termination charges
	During 2011, the Company recorded $58 million of charges related to the early termination of a maintenance service contract.
	Gains on sale of assets and other special charges
	During 2013, the Company adjusted its reserves for certain legal matters by $29 million and recorded approximately $11 million in accruals for future rent associated with the early retirement of four leased 757-200 aircraft. Additionally, the Company recorded a $5 million gain related to a contract termination and $3 million in gains on the sale of assets.
	During 2012, the Company recorded net gains of $46 million related to gains and losses on the disposal of aircraft and related parts and other assets.
	During 2011, other special charges included costs to terminate a maintenance service contract, adjustments to reserves for certain legal matters and gains and losses on the disposal of aircraft.
	Special Revenue Item. As discussed in Note 1 of this report, during the second quarter of 2011, United modified the previously existing co-branded credit card agreements with Chase as a result of the Merger. In accordance with Accounting Standards Update 2009-13, Multiple-Deliverable Revenue Arrangements - a consensus of the FASB Emerging Issues Task Force (“ASU 2009-13”), the Company retroactively adjusted its existing deferred revenue balance to reflect the value of any undelivered element remaining at the date of contract modification as if we had been applying ASU 2009-13 since the initiation of the Co-Brand Agreement. We applied this transition provision by revaluing the undelivered air transportation element using its new estimated selling price as determined in connection with the contract modification. This estimated selling price was lower than the rate at which the undelivered element had been deferred under the previous co-branded credit card contracts, and as a result, we recorded a one-time non-cash adjustment to decrease frequent flyer deferred revenue and increase special revenues by $107 million in June 2011.
	Accrual Activity
	Activity related to the accruals for severance and medical costs and future lease payments on permanently grounded aircraft is as follows (in millions):
		Severance/			Permanently
		Medical Costs			Grounded Aircraft
	Balance at December 31, 2010	$	102		$	41
	Accrual		21			5
	Payments		(68	)		(15	)
	Balance at December 31, 2011		55			31
	Accrual		170			(1	)
	Payments		(160	)		(25	)
	Balance at December 31, 2012		65			5
	Accrual		120			10
	Payments		(94	)		(4	)
	Balance at December 31, 2013	$	91		$	11
	The Company’s accrual and payment activity is primarily related to severance and other compensation expense associated with voluntary employee programs and the Merger, respectively.
	In March 2013, the Company agreed to sell up to 30 Boeing 757-200 aircraft to FedEx Corporation beginning in April 2013. As of December 31, 2012, the Company operated 133 such aircraft. Given the planned sale of these 30 aircraft, the Company evaluated the entire fleet and determined that no impairment existed. In conjunction with that sale, the Company recorded accelerated depreciation of $89 million on these aircraft for the year ended December 31, 2013, and this is classified as Operating expense: Depreciation and amortization in the statements of consolidated operations. The accelerated depreciation resulted from changes in the estimated useful lives and salvage values of the 30 aircraft as a result of the planned sale. These changes in estimate decreased net income by amounts disclosed above and reduced per share amounts by approximately $0.26 per UAL basic share ($0.23 per UAL diluted share) for the year ended December 31, 2013.
	Capacity Reduction. In February of 2014 the Company announced that it would be reducing its flying from Cleveland in stages beginning in April. The Company will reduce its average daily departures from Cleveland by around 60 percent. The decision to reduce flying was driven by continued losses in Cleveland, and the timing of the flight reductions was accelerated by industry-wide effects of new federal regulations that impact the Company and its regional partner flying. These new regulations impact the Company and its regional partner flying, as they have caused mainline airlines to hire regional pilots, while simultaneously significantly reducing the pool of new pilots from which regional carriers themselves can hire. Although this is an industry issue, it directly affects the Company and requires it to reduce regional partner flying, as several regional partners are beginning to have difficulty flying their schedules due to reduced new pilot availability. As a result, we will be reducing our average daily departures from Cleveland by approximately 60%. We expect to be able to keep almost all mainline departures (reducing only one of our 26 peak day mainline departures), but will need to reduce regional departures from Cleveland by over 70%. We will make these reductions in roughly one-third increments in each of early April, May and June 2014. When the schedule reductions are fully implemented in June, we plan to offer 72 peak-day flights from Cleveland, and serve 20 destinations from Cleveland on a non-stop basis. We currently expect to reduce up to 470 airport operations and catering positions in Cleveland. Those reductions will likely begin in June. The Company expects to record a special charge in 2014 related to the reduction in force and other contractual commitments at Cleveland. The Company is not currently able to estimate the amount of these charges or the time period in which they will be recorded, but such amounts could be significant.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2013
Segment Information	'
	NOTE 18 - SEGMENT INFORMATION
	Operating segments are defined as components of an enterprise with separate financial information, which are evaluated regularly by the chief operating decision maker and are used in resource allocation and performance assessments.
	The Company deploys its aircraft across its route network through a single route scheduling system to maximize its value. When making resource allocation decisions, the Company’s chief operating decision maker evaluates flight profitability data, which considers aircraft type and route economics. The Company’s chief operating decision maker makes resource allocation decisions to maximize the Company’s consolidated financial results. Managing the Company as one segment allows management the opportunity to maximize the value of its route network.
	The Company’s operating revenue by principal geographic region (as defined by the U.S. Department of Transportation) for the years ended December 31 is presented in the table below (in millions):
	2013	UAL		United
	Domestic (U.S. and Canada)	$	22,092	$	22,100
	Pacific		5,794		5,794
	Atlantic		7,132		7,132
	Latin America		3,261		3,261
	Total	$	38,279	$	38,287
	2012
	Domestic (U.S. and Canada)	$	21,276	$	21,284
	Pacific		6,040		6,040
	Atlantic		6,582		6,582
	Latin America		3,254		3,254
	Total	$	37,152	$	37,160
	2011
	Domestic (U.S. and Canada)	$	21,922	$	21,931
	Pacific		5,404		5,404
	Atlantic		6,675		6,675
	Latin America		3,109		3,109
	Total	$	37,110	$	37,119
	The Company attributes revenue among the geographic areas based upon the origin and destination of each flight segment. The Company’s operations involve an insignificant level of dedicated revenue-producing assets in geographic regions as the overwhelming majority of the Company’s revenue producing assets (primarily U.S. registered aircraft) can be deployed in any of its geographic regions.

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2013
Selected Quarterly Financial Data (Unaudited)	'
	NOTE 19 - SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
	UAL	Quarter Ended
	(In millions, except per share amounts)	March 31		June 30		September 30		December 31
	2013
	Operating revenue	$	8,721	$	10,001	$	10,228	$	9,329
	Income (loss) from operations		-264		770		508		235
	Net income (loss)		-417		469		379		140
	Basic earnings (loss) per share		-1.26		1.37		1.06		0.39
	Diluted earnings (loss) per share		-1.26		1.21		0.98		0.37
	2012
	Operating revenue	$	8,602	$	9,939	$	9,909	$	8,702
	Income (loss) from operations		-271		575		200		-465
	Net income (loss)		-448		339		6		-620
	Basic earnings (loss) per share		-1.36		1.02		0.02		-1.87
	Diluted earnings (loss) per share		-1.36		0.89		0.02		-1.87
	UAL’s quarterly financial data is subject to seasonal fluctuations and historically its second and third quarter financial results, which reflect higher travel demand, are better than its first and fourth quarter financial results. UAL’s quarterly results were impacted by the following significant items (in millions):
		Quarter Ended
		March 31		June 30		September 30		December 31
	2013
	Special charges (income):
	Integration-related costs	$	70	$	45	$	50	$	40
	Labor agreement costs		—		—		127		—
	Severance and benefits		14		—		—		91
	Asset impairments		—		—		—		33
	Additional costs associated with the temporarily grounded Boeing 787 aircraft		11		7		—		—
	(Gains) losses on sale of assets and other special charges, net		-3		—		34		1
	Total special items		92		52		211		165
	Income tax benefit		—		—		—		-7
	Total special items, net of tax	$	92	$	52	$	211	$	158
	2012
	Special charges (income):
	Integration-related costs	$	134	$	137	$	60	$	408
	Labor agreement costs		—		—		454		21
	Severance and benefits		49		76		—		—
	Asset impairments		6		—		—		24
	Gains on sale of assets and other special charges, net		-25		-7		—		-14
	Total special items		164		206		514		439
	Income tax benefit		-2		—		—		-9
	Total special items, net of tax	$	162	$	206	$	514	$	430
	See Note 17 of this report for further discussion of these items.

Schedule_II_Valuation_and_Qual

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2013
Schedule II Valuation and Qualifying Accounts	'
	Schedule II
	Valuation and Qualifying Accounts
	For the Years Ended December 31, 2013, 2012 and 2011
	(In millions)	Balance at		Additions		Deductions		Other		Balance at
		Beginning of		Charged to		(a)		(b)		End of
	Description	Period		Costs and						Period
				Expenses
	Allowance for doubtful accounts - UAL:
	2013	$	13	$	35	$	35	$	—	$	13
	2012		7		12		6		—		13
	2011		6		8		7		—		7
	Allowance for doubtful accounts - United:
	2013	$	13	$	35	$	35	$	—	$	13
	2012		7		12		6		—		13
	2011		6		8		7		—		7
	Obsolescence allowance—spare parts - UAL:
	2013	$	125	$	38	$	1	$	—	$	162
	2012		89		40		4		—		125
	2011		64		31		6		—		89
	Obsolescence allowance—spare parts - United:
	2013	$	125	$	38	$	1	$	—	$	162
	2012		89		40		4		—		125
	2011		64		31		6		—		89
	Valuation allowance for deferred tax assets - UAL:
	2013	$	4,603	$	7	$	888	$	84	$	3,806
	2012		4,137		487		21		—		4,603
	2011		4,171		333		367		—		4,137
	Valuation allowance for deferred tax assets - United:
	2013	$	4,503	$	8	$	898	$	163	$	3,776
	2012		4,048		661		206		—		4,503
	2011		4,008		371		331		—		4,048
	(a) Deduction from reserve for purpose for which reserve was created.
	(b) See Note 7 to the financial statements included in Part II, Item 8 of this report for additional information related to other valuation allowance adjustments.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Use of Estimates and Reclassifications	'
	(a)	Use of Estimates and Reclassifications—The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. Actual results could differ from those estimates.
	Certain prior year cash flows from operating activities have been reclassified to conform to the current year presentation.
Passenger Revenue Recognition	'
	(b)	Passenger Revenue Recognition—The value of unused passenger tickets is included in current liabilities as advance ticket sales. The Company records passenger ticket sales and tickets sold by other airlines for use on United as passenger revenue when the transportation is provided or upon estimated breakage. Tickets sold by other airlines are recorded at the estimated values to be billed to the other airlines. Differences between amounts billed and the actual amounts may be rejected and rebilled or written off if the amount recorded was different from the original estimate. When necessary, the Company records a reserve against our interline billings and payables if historical experience indicates that these amounts are different. Non-refundable tickets generally expire on the date of the intended flight, unless the date is extended by notification from the customer on or before the intended flight date.
	Fees charged in association with changes or extensions to non-refundable tickets are recorded as other revenue at the time the fee is incurred. The fare on the changed ticket, including any additional collection, is deferred and recognized in accordance with our transportation revenue recognition policy at the time the transportation is provided. Change fees related to non-refundable tickets are considered a separate transaction from the air transportation because they represent a charge for the Company’s additional service to modify a previous sale. Therefore, the pricing of the change fee and the initial customer order are separately determined and represent distinct earnings processes. Refundable tickets expire after one year.
	The Company records an estimate of breakage revenue on the flight date for tickets that will expire unused. These estimates are based on the evaluation of actual historical results and forecasted trends.
	The Company recognizes cargo and other revenue as service is provided.
	Under our capacity purchase agreements (“CPAs”) with regional carriers, we purchase all of the capacity related to aircraft covered by the contracts and are responsible for selling all of the related seat inventory. We record the passenger revenue and related expenses as separate operating revenue and expense in the consolidated statement of operations.
	Accounts receivable primarily consist of amounts due from credit card companies and customers of our aircraft maintenance and cargo transportation services. We provide an allowance for uncollectible accounts equal to the estimated losses expected to be incurred based on historical write-offs and other specific analyses. Bad debt expense and write-offs were not material for the years ended December 31, 2013, 2012 and 2011.
Frequent Flyer Accounting	'
	(c)	Frequent Flyer Accounting—United has a frequent flyer program that is designed to increase customer loyalty. Program participants earn mileage credits (“miles”) by flying on United and certain other participating airlines. Program participants can also earn miles through purchases from other non-airline partners that participate in United’s loyalty program. We sell miles to these partners, which include credit card issuers, retail merchants, hotels, car rental companies and our participating airline partners. Miles can be redeemed for free (other than taxes and government imposed fees), discounted or upgraded air travel and non-travel awards. The Company records its obligation for future award redemptions using a deferred revenue model.
	Miles Earned in Conjunction with Flights
	In the case of the sale of air services, the Company recognizes a portion of the ticket sales as revenue when the air transportation occurs and defers a portion of the ticket sale representing the value of the related miles as a multiple-deliverable revenue arrangement.
	The Company determines the estimated selling price of the air transportation and miles as if each element is sold on a separate basis. The total consideration from each ticket sale is then allocated to each of these elements individually on a pro rata basis. The Company’s estimated selling price of miles is based on the price we sell miles to Star Alliance partners in our reciprocal frequent flyer agreements as the best estimate of selling price for these miles.
	On December 9, 2013, US Airways and American Airlines closed their merger transaction and, as a result of the merger transaction, we anticipate US Airways will exit Star Alliance on March 30, 2014. Effective with the exit date of US Airways from Star Alliance, the Company will update its estimated selling price for miles to using the equivalent ticket value less fulfillment discount, as the estimated selling price for miles. The equivalent ticket value used as the basis for the estimated selling price of miles is based on the prior 12 months’ weighted average equivalent ticket value of similar fares as those used to settle award redemptions while taking into consideration such factors as redemption pattern, cabin class and geographic region. Management believes this change is a change in estimate, and as such, the change will be applied on a prospective basis. The estimated impact of this change on consolidated revenue is not expected to be material in 2014.
	Co-branded Credit Card Partner Mileage Sales
	United also has a significant contract to sell frequent flyer miles to its co-branded credit card partner, Chase Bank USA, N.A. (“Chase”). On June 9, 2011, this contract was modified and United entered into The Consolidated Amended and Restated Co-Branded Card Marketing Services Agreement (the “Co-Brand Agreement”) with Chase.
	United identified five revenue elements in the Co-Brand Agreement: the air transportation element represented by the value of the mile (generally resulting from its redemption for future air transportation and whose fair value is described above); use of the United brand and access to frequent flyer member lists; advertising; baggage services; and airport lounge usage (together, excluding “the air transportation element”, the “marketing-related deliverables”).
	The fair value of the elements is determined using management’s estimated selling price of each element. The objective of using the estimated selling price based methodology is to determine the price at which we would transact a sale if the product or service were sold on a stand-alone basis. Accordingly, we determine our best estimate of selling price by considering multiple inputs and methods including, but not limited to, discounted cash flows, brand value, volume discounts, published selling prices, number of miles awarded and number of miles redeemed. The Company estimated the selling prices and volumes over the term of the Co-Brand Agreement in order to determine the allocation of proceeds to each of the multiple elements to be delivered. The method for determining the selling price of the mile component is changing March 30, 2014, as described above. We also evaluate volumes on an annual basis, which may result in a change in the allocation of estimated selling price on a prospective basis.
	The Company records passenger revenue related to the air transportation element when the transportation is delivered. The other elements are generally recognized as Other operating revenue when earned.
	Expiration of Miles
	The Company accounts for miles sold and awarded that will never be redeemed by program members, which we refer to as breakage. The Company reviews its breakage estimates annually based upon the latest available information regarding redemption and expiration patterns. The Company re-evaluated its population breakage estimates for a portion of its miles, which were previously not subject to an expiration policy, and increased the estimate of miles in the population expected to ultimately expire.
	The Company’s estimate of the expected expiration of miles requires significant management judgment. Current and future changes to expiration assumptions or to the expiration policy, or to program rules and program redemption opportunities, may result in material changes to the deferred revenue balance as well as recognized revenues from the programs. Effective March 30, 2014, the Company will incorporate a fulfillment discount into its best estimate of selling price which incorporates the expected redemption of miles.
	Other Information
	The following table provides additional information related to the frequent flyer program (in millions):
	Year Ended		Cash Proceeds		Other Revenue		Increase in Frequent		Increase
	December 31,		from Miles Sold		Recognized Upon		Flyer Deferred		(Decrease)  in
					Award of Miles		Revenue for Miles		Advanced
					to Third-Party		Awarded (b)		Purchase of
					Customers (a)				Miles (c)
	2013		$	2,903	$	903	$	2,174	$	-174
	2012			2,852		816		2,036		—
	2011			3,121		566		2,357		198
	(a) This amount represents other revenue recognized during the period from the sale of miles to third parties, representing the marketing-related deliverable services component of the sale.
	(b) This amount represents the increase to frequent flyer deferred revenue during the period.
	(c) This amount represents the net increase (decrease) in the advance purchase of miles obligation due to cash payments for the sale of miles in excess of (less than) miles awarded to customers.
Cash and Cash Equivalents and Restricted Cash	'
	(d)	Cash and Cash Equivalents and Restricted Cash— Highly liquid investments with a maturity of three months or less on their acquisition date are classified as cash and cash equivalents.
	Restricted cash primarily includes cash collateral associated with workers’ compensation obligations, reserves for institutions that process credit card ticket sales and cash collateral received from fuel hedge counterparties. Restricted cash is classified as short-term or long-term in the consolidated balance sheets based on the expected timing of return of the assets to the Company. Airline industry practice includes classification of restricted cash flows as either investing cash flows or operating cash flows. Cash flows related to restricted cash activity are classified as investing activities because the Company considers restricted cash arising from these activities similar to an investment.
Short-term Investments	'
	(e)
	Short-term Investments—Short-term investments are classified as available-for-sale and are stated at fair value. Realized gains and losses on sales of investments are reflected in nonoperating income (expense) in the consolidated statements of operations. Unrealized gains and losses on available-for-sale securities are reflected as a component of accumulated other comprehensive income/loss.
Aircraft Fuel, Spare Parts and Supplies	'
	(f)
	Aircraft Fuel, Spare Parts and Supplies—The Company accounts for aircraft fuel, spare parts and supplies at average cost and provides an obsolescence allowance for aircraft spare parts and supplies.
Property and Equipment	'
	(g)	Property and Equipment—The Company records additions to owned operating property and equipment at cost when acquired. Property under capital leases and the related obligation for future lease payments are recorded at an amount equal to the initial present value of those lease payments. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized as property and equipment. It is the Company’s policy to record compensation from delays in delivery of aircraft as a reduction of the cost of the related aircraft.
	Depreciation and amortization of owned depreciable assets is based on the straight-line method over the assets’ estimated useful lives. Leasehold improvements are amortized over the remaining term of the lease, including estimated facility renewal options when renewal is reasonably assured at key airports, or the estimated useful life of the related asset, whichever is less. Properties under capital leases are amortized on the straight-line method over the life of the lease or, in the case of certain aircraft, over their estimated useful lives, whichever is shorter. Amortization of capital lease assets is included in depreciation and amortization expense. The estimated useful lives of property and equipment are as follows:
			Estimated Useful Life (in years)
	Aircraft and related rotable parts			25 to 30
	Buildings			25 to 45
	Other property and equipment			4 to 15
	Computer software			5
	Building improvements			1 to 40
	As of December 31, 2013 and 2012, the Company had a carrying value of computer software of $290 million and $302 million, respectively. For the years ended December 31, 2013, 2012 and 2011, the Company’s depreciation expense related to computer software was $72 million, $81 million and $133 million, respectively. Aircraft and aircraft parts were assumed to have residual values with a range of 10% to 11% of original cost, depending on type, and other categories of property and equipment were assumed to have no residual value.
Maintenance and Repairs	'
	(h)
	Maintenance and Repairs—The cost of maintenance and repairs, including the cost of minor replacements, is charged to expense as incurred, except for costs incurred under our power-by-the-hour (“PBTH”) engine maintenance agreements. PBTH contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Under PBTH agreements, the Company recognizes expense at a level rate per engine hour, unless the level of service effort and the related payments during the period are substantially consistent, in which case the Company recognizes expense based on the amounts paid.
Lease Fair Value Adjustments	'
	(i)
	Lease Fair Value Adjustments—Lease fair value adjustments, which arose from recording operating leases at fair value under fresh start accounting or the Merger, are amortized on a straight line basis over the related lease term.
Regional Capacity Purchase	'
	(j)
	Regional Capacity Purchase—Payments made to regional carriers under CPAs are reported in Regional capacity purchase in our consolidated statements of operations.
Advertising	'
	(k)	Advertising—Advertising costs, which are included in Other operating expenses, are expensed as incurred. Advertising expenses were $178 million, $154 million and $142 million for the years ended December 31, 2013, 2012 and 2011, respectively.
Intangibles	'
	(l)	Intangibles—The Company has finite-lived and indefinite-lived intangible assets, including goodwill. As of December 31, 2013, goodwill represents the excess purchase price over the fair values of tangible and identifiable intangible assets acquired and liabilities assumed from Continental in the Merger. Finite-lived intangible assets are amortized over their estimated useful lives. Goodwill and indefinite-lived intangible assets are not amortized but are reviewed for impairment annually or more frequently if events or circumstances indicate that the asset may be impaired. Goodwill and indefinite-lived assets are reviewed for impairment on an annual basis as of October 1, or on an interim basis whenever a triggering event occurs. See Notes 2 and 17 for additional information related to intangibles.
Long-Lived Asset Impairments	'
	(m)	Long-Lived Asset Impairments—The Company evaluates the carrying value of long-lived assets and intangible assets subject to amortization whenever events or changes in circumstances indicate that an impairment may exist. For purposes of this testing, the Company has generally identified the aircraft fleet type as the lowest level of identifiable cash flows for purposes of testing aircraft for impairment. An impairment charge is recognized when the asset’s carrying value exceeds its net undiscounted future cash flows and its fair market value. The amount of the charge is the difference between the asset’s carrying value and fair market value. See Note 17 for information related to asset impairments.
Share-Based Compensation	'
	(n)
	Share-Based Compensation—The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. The resulting cost is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period. Obligations for restricted stock units (“RSUs”) are remeasured at fair value throughout the requisite service period on the last day of each reporting period based upon UAL’s stock price. In addition to the service requirement, certain RSUs have performance metrics that must be achieved prior to vesting. These awards are accrued based on the expected level of achievement at each reporting period. A cumulative adjustment is recorded on the last day of each reporting period to adjust compensation expense based on both UAL’s stock price and the then current level of expected performance achievement for the performance-based awards. See Note 5 for additional information on UAL’s share-based compensation plans.
Ticket Taxes	'
	(o)
	Ticket Taxes—Certain governmental taxes are imposed on the Company’s ticket sales through a fee included in ticket prices. The Company collects these fees and remits them to the appropriate government agency. These fees are recorded on a net basis (excluded from operating revenue).
Retirement of Leased Aircraft	'
	(p)
	Retirement of Leased Aircraft—The Company accrues for estimated lease costs over the remaining term of the lease at the present value of future minimum lease payments, net of estimated sublease rentals (if any), in the period that aircraft are permanently removed from service. When reasonably estimable and probable, the Company estimates maintenance lease return condition obligations for items such as minimum aircraft and engine conditions specified in leases and accrues these amounts over the lease term while the aircraft are operating, and any remaining unrecognized estimated obligations are accrued in the period that an aircraft is removed from service.
Uncertain Income Tax Positions	'
	(q)	Uncertain Income Tax Positions—The Company has recorded reserves for income taxes and associated interest that may become payable in future years. Although management believes that its positions taken on income tax matters are reasonable, the Company nevertheless has established tax and interest reserves in recognition that various taxing authorities may challenge certain of the positions taken by the Company, potentially resulting in additional liabilities for taxes and interest. The Company’s uncertain tax position reserves are reviewed periodically and are adjusted as events occur that affect its estimates, such as the availability of new information, the lapsing of applicable statutes of limitation, the conclusion of tax audits, the measurement of additional estimated liability, the identification of new tax matters, the release of administrative tax guidance affecting its estimates of tax liabilities, or the rendering of relevant court decisions. See Note 7 for further information related to uncertain income tax positions.
Labor Costs	'
	(r)
	Labor Costs—The Company records expenses associated with amendable labor agreements when the employee group has earned the compensation and the amounts are probable and estimable. These include costs associated with lump sum cash payments that would be made in conjunction with the ratification of labor agreements. To the extent these upfront costs are in lieu of future pay increases, they would be capitalized and amortized over the term of the labor agreements. If not, these amounts would be expensed once earned and when they become probable and estimable.
Third Party Business	'
	(s)
	Third-Party Business—The Company has third-party business revenue that includes fuel sales, catering, ground handling, maintenance services and frequent flyer award non-air redemptions, and third-party business revenue is recorded in other revenue. The Company has a contract to sell aircraft fuel to a third party which is earnings-neutral but results in revenue and expense, specifically cost of sale which is unrelated to the operation of the airline. The Company also incurs third-party business expenses, such as maintenance, ground handling and catering services for third parties, fuel sales and non-air mileage redemptions, and those third-party business expenses are recorded in Other operating expenses.
Related party receivables	'
	(t)
	Related party receivables—United has receivables from affiliates of $232 million that are classified against stockholder’s equity as of December 31, 2013 as a result of an anticipated distribution of the amount via an equity transaction planned in early 2014.
Recently Issued Accounting Standards	'
	(u)
	Recently Issued Accounting Standards—In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update No. 2013-02 (“ASU 2013-02”), Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. Some of the key amendments require the Company to present, either on the face of the statement of operations or in the notes to the consolidated financial statements, the effects on the line items of net income of significant amounts reclassified out of accumulated other comprehensive income, but only if the amount reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period. For amounts that are not required to be reclassified in their entirety to net income, the Company is required to cross-reference to other disclosures that provide additional detail about those amounts. ASU 2013-02 became effective for the Company’s annual and interim periods beginning January 1, 2013, and the required disclosures are included in Note 6 of this report.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Schedule of Information Related to Amounts Recorded Related to Frequent Flyer Programs	'
	The following table provides additional information related to the frequent flyer program (in millions):
	Year Ended	Cash Proceeds		Other Revenue		Increase in Frequent		Increase
	December 31,	from Miles Sold		Recognized Upon		Flyer Deferred		(Decrease)  in
				Award of Miles		Revenue for Miles		Advanced
				to Third-Party		Awarded (b)		Purchase of
				Customers (a)				Miles (c)
	2013	$	2,903	$	903	$	2,174	$	-174
	2012		2,852		816		2,036		—
	2011		3,121		566		2,357		198
	(a) This amount represents other revenue recognized during the period from the sale of miles to third parties, representing the marketing-related deliverable services component of the sale.
	(b) This amount represents the increase to frequent flyer deferred revenue during the period.
	(c) This amount represents the net increase (decrease) in the advance purchase of miles obligation due to cash payments for the sale of miles in excess of (less than) miles awarded to customers.
Estimated Useful Lives of Property and Equipment	'
	The estimated useful lives of property and equipment are as follows:
		Estimated Useful Life (in years)
	Aircraft and related rotable parts		25 to 30
	Buildings		25 to 45
	Other property and equipment		4 to 15
	Computer software		5
	Building improvements		1 to 40

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Other Intangible Assets	'
	The following table presents information about the Company’s goodwill and other intangible assets at December 31 (in millions):
			2013				2012
	Item	Asset life (a)	Gross Carrying		Accumulated		Gross Carrying		Accumulated
			Amount		Amortization		Amount		Amortization
	Goodwill		$	4,523			$	4,523
	Finite-lived intangible assets
	Airport slots and gates	8	$	98	$	88	$	99	$	75
	Hubs	20		145		59		145		52
	Patents and tradenames	3		108		108		108		99
	Frequent flyer database (b)	22		1,177		536		1,177		447
	Contracts	13		167		86		167		75
	Other	25		109		56		109		44
	Total		$	1,804	$	933	$	1,805	$	792
	Indefinite-lived intangible assets
	Airport slots and gates		$	963			$	981
	Route authorities			1,605				1,606
	Tradenames and logos			593				593
	Alliances			404				404
	Total		$	3,565			$	3,584
	(a) Weighted average life expressed in years.
	(b) The frequent flyer database is amortized based on an accelerated amortization schedule to reflect utilization of the assets. Estimated cash flows correlating to the expected attrition rate of customers in the frequent flyer database is considered in the determination of the amortization schedules.

Earnings_Loss_Per_Share_Tables

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Computation of Earnings Per Share	'
	The computations of UAL’s basic and diluted earnings (loss) per share and the number of securities that have been excluded from the computation of diluted earnings per share amounts because they were antidilutive are set forth below (in millions, except per share amounts):
		2013		2012		2011
	Basic earnings (loss) per share:
	Net income (loss)	$	571	$	-723	$	840
	Less: Income allocable to participating securities		-2		—		-3
	Earnings (loss) available to common stockholders	$	569	$	-723	$	837
	Basic weighted-average shares outstanding		348		331		329
	Earnings (loss) per share, basic	$	1.64	$	-2.18	$	2.54
	Diluted earnings (loss) per share:
	Earnings (loss) available to common stockholders	$	569	$	-723	$	837
	Effect of dilutive securities		26		—		27
	Earnings (loss) available to common stockholders including the effect of dilutive securities	$	595	$	-723	$	864
	Diluted shares outstanding:
	Basic weighted-average shares outstanding		348		331		329
	Effect of convertible notes		42		—		52
	Effect of employee stock options		—		—		2
	Diluted weighted-average shares outstanding		390		331		383
	Earnings (loss) per share, diluted	$	1.53	$	-2.18	$	2.26
	Potentially dilutive shares excluded from diluted per share amounts:
	Restricted stock and stock options		3		5		6
	Convertible notes		4		61		15
			7		66		21

ShareBased_Compensation_Plans_

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Schedule of Share-Based Compensation Plan Cost	'
	The following table provides information related to UAL’s share-based compensation plan cost, for the years ended December 31 (in millions):
		2013		2012		2011
	Compensation cost: (a)
	RSUs	$	88	$	37	$	18
	Restricted stock		11		13		12
	Share-based awards converted to cash awards		1		6		19
	Stock options		—		1		5
	Total	$	100	$	57	$	54
	(a) All compensation cost is recorded to Salaries and related costs, with the exception of $9 million, $9 million and $17 million in 2013, 2012 and 2011, respectively, that was recorded in integration-related costs as a component of special charges.
Schedule of Unearned Compensation and Weighted Average Remaining Period for Outstanding Share-Based Awards	'
	The table below summarizes UAL’s unearned compensation and weighted-average remaining period to recognize costs for all outstanding share-based awards for the year ended December 31, 2013 (in millions, except as noted):
		Unearned		Weighted-
		Compensation		Average
				Remaining
				Period (in
				years)
	RSUs	$	36		1.3
	Restricted stock		8		1.4
	Stock options		—		0.6
	Total	$	44
Schedule Of Restricted Stock Unit and Restricted Stock Activity	'
	The table below summarizes UAL’s RSUs and restricted stock activity for the years ended December 31 (shares in millions):
		RSUs		Restricted Stock		Weighted-
						Average
						Grant  Price
	Non-vested at December 31, 2010		—		1	$	17.20
	Granted		4		1		23.87
	Vested		—		-1		22.26
	Surrendered		-1		—		23.95
	Non-vested at December 31, 2011		3		1		23.33
	Granted		2		1		24.01
	Vested		—		-1		23.05
	Surrendered		-1		—		24.01
	Non-vested at December 31, 2012		4		1		23.94
	Granted		2		1		25.98
	Vested		-1		-1		23.93
	Surrendered		—		—		24.76
	Non-vested at December 31, 2013		5		1		25.02
Stock Option Activity	'
	The table below summarizes UAL stock option activity for the years ended December 31 (in millions, except as noted):
		Options		Weighted-		Weighted-		Aggregate
				Average		Average		Intrinsic Value
				Exercise Price		Remaining
						Contractual
						Life (in years)
	Outstanding at December 31, 2010		11	$	21.70
	Exercised		-2		10.77			$	33
	Surrendered		-2		29.07
	Outstanding at December 31, 2011		7		23.80
	Exercised		-1		12.42				14
	Surrendered		-1		30.50
	Outstanding at December 31, 2012		5		25.60
	Exercised		-2		16.28				27
	Surrendered		—		27.49
	Outstanding at December 31, 2013		3		31.63		2.2		18
	Exercisable at December 31, 2013		3		32.00		2.2		16

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2013
Components of Accumulated Other Comprehensive Income (Loss), Net of Tax	'
	The tables below present the components of the Company’s accumulated other comprehensive income (loss) (“AOCI”), net of tax (in millions):
	UAL (a)		Pension and			Unrealized		Other		Total
			Other			Gains (Losses)
			Postretirement			on Derivatives
			Unrecognized
			Actuarial
			Gains (Losses)
			and Prior
			Service Cost
	Balance at December 31, 2010		$	152		$	240	$	-5	$	387
	Other comprehensive loss before reclassifications			-440			163		—		-277
	Amounts reclassified from accumulated other comprehensive income			-24			-503		—		-527
	Net current-period other comprehensive income (loss)			-464			-340		—		-804
	Balance at December 31, 2011		$	-312		$	-100	$	-5	$	-417
	Other comprehensive loss before reclassifications			-747			-51		11		-787
	Amounts reclassified from accumulated other comprehensive income			17			141		—		158
	Net current-period other comprehensive income (loss)			-730			90		11		-629
	Balance at December 31, 2012		$	-1,042		$	-10	$	6	$	(1,046)
	Other comprehensive income before reclassifications			1,584	(b)		39		7		1,630
	Amounts reclassified from accumulated other comprehensive income			42			-18		—		24
	Net current-period other comprehensive income (loss)			1,626			21		7		1,654
	Balance at December 31, 2013		$	584		$	11	$	13	$	608
	Details about AOCI Components		Amount Reclassified from AOCI to							Affected Line Item in
			Income							the Statement Where
										Net Income is Presented
			Year Ended December 31,
			2013			2012		2011
	Derivatives designated as cash flow hedges
	Fuel contracts-reclassifications of (gains) losses into earnings (c)		$	-18		$	141	$	-503	Aircraft fuel
	Amortization of pension and post-retirement items
	Amortization of unrecognized (gains) losses and prior service cost and the effect of curtailments and settlements (c) (d)		$	42		$	17	$	-24	Salaries and related costs
	(a) UAL and United amounts are substantially the same except for an additional $6 million of income tax benefit at United in 2013. In addition, United had additional (losses) gains related to investments and other of $(2) million, $1 million and $1 million in 2011, 2012 and 2013, respectively.
	(b) For 2013, prior service credits increased by $331 million and actuarial gains increased by approximately $1.3 billion. Amounts for 2012 and 2011 were not material.
	(c)	Income tax expense offset by Company’s valuation allowance.
	(d) This accumulated other comprehensive income component is included in the computation of net periodic pension costs (see Note 8 of this report for additional details).

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Components of Income Tax Expense (Benefit)	'
	The significant components of the income tax expense (benefit) are as follows (in millions):
	2013	UAL		United
	Current	$	-18	$	-18
	Deferred		-14		1
		$	-32	$	-17
	2012
	Current	$	-14	$	-9
	Deferred		13		13
		$	-1	$	4
	2011
	Current	$	11	$	3
	Deferred		-6		-5
		$	5	$	-2
Income Tax Provision Differed from Amounts Computed at Statutory Federal Income Tax Rate	'
	The income tax provision differed from amounts computed at the statutory federal income tax rate, as follows (in millions):
	Year ended December 31, 2013	UAL		United
	Income tax provision at statutory rate	$	189	$	223
	State income taxes, net of federal income tax		5		5
	Foreign income taxes		3		3
	Nondeductible employee meals		15		15
	Nondeductible interest expense		—		—
	Derivative market adjustment		—		-24
	Nondeductible compensation		3		3
	State rate change		-33		-33
	Valuation allowance		-219		-229
	Other, net		5		20
		$	-32	$	-17
	Year ended December 31, 2012
	Income tax provision at statutory rate	$	-253	$	-230
	State income taxes, net of federal income tax		-15		-7
	Foreign income taxes		7		7
	Nondeductible employee meals		12		12
	Nondeductible interest expense		19		19
	Derivative market adjustment		—		-15
	Nondeductible compensation		5		5
	Valuation allowance		234		223
	Other, net		-10		-10
		$	-1	$	4
	Year Ended December 31, 2011
	Income tax provision at statutory rate	$	298	$	299
	State income taxes, net of federal income tax		-19		-17
	Nondeductible acquisition costs		-17		-17
	Nondeductible employee meals		12		12
	Nondeductible interest expense		13		13
	Derivative market adjustment		—		10
	Nondeductible compensation		9		10
	Valuation allowance		-294		-315
	Other, net		3		3
		$	5	$	-2
Components of Deferred Tax Assets and Liabilities	'
	Temporary differences and carryforwards that give rise to deferred tax assets and liabilities at December 31, 2013 and 2012 were as follows (in millions):
		UAL				United
		December 31,				December 31,
		2013		2012		2013		2012
	Deferred income tax asset (liability):
	Federal and state net operating loss (“NOL”) carryforwards	$	3,221	$	3,025	$	3,158	$	2,957
	Frequent flyer deferred revenue		2,254		2,425		2,254		2,426
	Employee benefits, including pension, postretirement, medical and the Pension Benefit Guaranty Corporation (“PBGC”) notes		1,701		2,488		1,701		2,491
	Lease fair value adjustment		123		259		123		259
	AMT credit carryforwards		233		251		233		251
	Other assets		217		947		217		882
	Less: Valuation allowance		-3,806		-4,603		-3,776		-4,503
	Total deferred tax assets (a)	$	3,943	$	4,792	$	3,910	$	4,763
	Depreciation, capitalized interest and other	$	-3,201	$	-3,705	$	-3,201	$	-3,702
	Intangibles		-1,585		-1,578		-1,585		-1,579
	Other liabilities		-144		-509		-111		-406
	Total deferred tax liabilities	$	-4,930	$	-5,792	$	-4,897	$	-5,687
	Net deferred tax liability (a)	$	-987	$	-1,000	$	-987	$	-924
	(a) During 2013, UAL identified adjustments to the components of the deferred taxes. As a result of this analysis, changes in deferred tax assets and liabilities occurred, and are reflected in 2013 deferred tax balances. UAL and United increased their valuation allowance to reflect these adjustments by $84 million and $163 million, respectively. United separately identified an adjustment of $68 million to increase its deferred tax liability with an offset to United-only equity to correct an error made in prior years. This item did not affect the consolidated accounts of UAL. It was corrected in the current period as it was not considered material to United’s prior year reported financial position.
Reconciliation of Unrecognized Tax Benefits	'
	The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits related to the Company’s uncertain tax positions (in millions):
		2013		2012		2011
	Balance at January 1,	$	19	$	24	$	32
	Decrease in unrecognized tax benefits relating to settlements with taxing authorities		—		-12		—
	Increase (decrease) in unrecognized tax benefits as a result of tax positions taken during a prior period		—		8		-9
	Decrease in unrecognized tax benefits relating from a lapse of the statute of limitations		-5		-1		—
	Increase in unrecognized tax benefits as a result of tax positions taken during the current period		—		—		1
	Balance at December 31,	$	14	$	19	$	24

Pension_and_Other_Postretireme1

Pension and Other Postretirement Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Reconciliation of Change in Projected Benefit Obligation and Plan Assets	'
	The following table sets forth the reconciliation of the beginning and ending balances of the benefit obligation and plan assets, the funded status and the amounts recognized in these financial statements for the defined benefit and other postretirement plans (in millions):
		Pension Benefits
		Year Ended			Year Ended
		December 31, 2013			December 31, 2012
	Accumulated benefit obligation:	$	3,383		$	3,978
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year	$	4,526		$	3,708
	Service cost		121			99
	Interest cost		191			184
	Actuarial (gain) loss		-464			702
	Gross benefits paid and settlements		-269			-162
	Curtailments		-84			—
	Other		-21			-5
	Projected benefit obligation at end of year	$	4,000		$	4,526
	Change in plan assets:
	Fair value of plan assets at beginning of year	$	2,157		$	1,868
	Actual gain on plan assets		239			223
	Employer contributions		277			228
	Gross benefits paid and settlements		-269			-162
	Other		-7			—
	Fair value of plan assets at end of year	$	2,397		$	2,157
	Funded status—Net amount recognized	$	-1,603		$	-2,369
		Other Postretirement Benefits
		Year Ended			Year Ended
		December 31, 2013			December 31, 2012
	Change in benefit obligation:
	Benefit obligation at beginning of year	$	2,743		$	2,541
	Service cost		52			50
	Interest cost		110			124
	Plan participants’ contributions		67			77
	Actuarial (gain) loss		-640			110
	Federal subsidy		7			13
	Plan amendments		-331			22
	Curtailments		8			—
	Gross benefits paid		-197			-194
	Benefit obligation at end of year	$	1,819		$	2,743
	Change in plan assets:
	Fair value of plan assets at beginning of year	$	58		$	58
	Actual return on plan assets		1			1
	Employer contributions		128			116
	Plan participants’ contributions		67			77
	Benefits paid		-197			-194
	Fair value of plan assets at end of year		57			58
	Funded status—Net amount recognized	$	-1,762		$	-2,685
Amounts Recognized in Consolidated Balance Sheet and Accumulated Other Comprehensive Income (Loss)	'
		Pension Benefits
		December 31, 2013			December 31, 2012
	Amounts recognized in the consolidated balance sheets consist of:
	Noncurrent asset	$	49		$	35
	Current liability		-2			-4
	Noncurrent liability		-1,650			-2,400
	Total liability	$	-1,603		$	-2,369
	Amounts recognized in accumulated other comprehensive income (loss) consist of:
	Net actuarial loss	$	-162		$	-826
	Prior service credit		—			2
	Total accumulated other comprehensive loss	$	-162		$	-824
		Other Postretirement Benefits
		December 31, 2013			December 31, 2012
	Amounts recognized in the consolidated balance sheets consist of:
	Current liability	$	-59		$	-71
	Noncurrent liability		-1,703			-2,614
	Total liability	$	-1,762		$	-2,685
	Amounts recognized in accumulated other comprehensive income (loss) consist of:
	Net actuarial gain (loss)	$	555		$	-79
	Prior service credit (cost)		306			-24
	Total accumulated other comprehensive income (loss)	$	861		$	-103
Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets	'
	The following information relates to all pension plans with an accumulated benefit obligation and a projected benefit obligation in excess of plan assets at December 31 (in millions):
		2013			2012
	Projected benefit obligation	$	3,820		$	4,387
	Accumulated benefit obligation		3,245			3,869
	Fair value of plan assets		2,176			1,991
Components Of Net Periodic Benefit Cost	'
	Net periodic benefit cost for the years ended December 31 included the following components (in millions):
		2013						2012				2011
		Pension			Other			Pension		Other		Pension				Other
		Benefits			Postretirement			Benefits		Postretirement		Benefits				Postretirement
					Benefits					Benefits						Benefits
	Service cost	$	121		$	52		$	99	$	50	$	88			$	47
	Interest cost		191			110			184		124		178				127
	Expected return on plan assets		-163			-2			-138		-2		-140				-2
	Curtailment loss		2			2			—		—		—				—
	Amortization of prior service credits		—			-3			-1		—		-2				—
	Settlement (gain) loss		-10			—			1		—		1				—
	Amortization of unrecognized actuarial (gain) loss		48			3			21		-3		-20				-2
	Net periodic benefit cost	$	189		$	162		$	166	$	169	$	105			$	170
Amortized Accumulated Other Comprehensive Income Into Net Periodic Benefit Cost	'
	The estimated amounts that will be amortized in 2014 for actuarial (gains) losses are as follows (in millions):
		Pension			Other
		Benefits			Postretirement
					Benefits
	Actuarial (gain) loss to be reclassified from accumulated other comprehensive income into net periodic benefit cost	$	9		$	-46
Assumptions Used for Benefit Plans	'
	The assumptions used for the benefit plans were as follows:
			Pension Benefits
	Assumptions used to determine benefit obligations		2013			2012
	Discount rate		5.09%			4.19%
	Rate of compensation increase		3.49%			2.49%
	Assumptions used to determine net expense
	Discount rate		4.48%			5.02%
	Expected return on plan assets		7.56%			7.54%
	Rate of compensation increase		2.48%			2.48%
		Other Postretirement Benefits
	Assumptions used to determine benefit obligations	2013			2012
	Discount rate		4.94%			4.12%
	Assumptions used to determine net expense
	Discount rate		4.12%			4.92%
	Expected return on plan assets		4.00%			4.00%
	Health care cost trend rate assumed for next year		7.25%			6.75%
	Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2020)		5.00%			5.00%
Allocation of Plan Asset	'
	United’s plan assets are allocated within the following guidelines:
		Percent of Total		Expected Long-Term
				Rate of Return
	Equity securities	42-52    %		9.5    %
	Fixed-income securities	26-34		5.5
	Alternatives	15-21		7.5
	Other	7-Mar		4.5
Effect of One-Percentage-Point Change in Assumed Health Care Trend Rate	'
	A 1% change in the assumed health care trend rate for the Company would have the following additional effects (in millions):
		1% Increase			1% Decrease
	Effect on total service and interest cost for the year ended December 31, 2013	$	21		$	(17	)
	Effect on postretirement benefit obligation at December 31, 2013		213			(186	)
Pension and Other Postretirement Plan Assets	'
	The following tables present information about the United’s pension and other postretirement plan assets at December 31 (in millions):
		2013												2012
	Pension Plan Assets:	Total			Level 1			Level 2		Level 3				Total				Level 1		Level 2		Level 3
	Equity securities funds	$	1,158		$	389		$	769	$	—			$	1,034			$	383	$	651	$	—
	Fixed-income securities		702			—			698		4				611				—		609		2
	Alternatives		405			—			199		206				394				—		234		160
	Insurance contract		26			—			—		26				36				—		—		36
	Other investments		106			—			106		—				82				—		82		—
	Total	$	2,397		$	389		$	1,772	$	236			$	2,157			$	383	$	1,576	$	198
	Other Postretirement Benefit Plan Assets:
	Deposit administration fund	$	57		$	—		$	—	$	57			$	58			$	—	$	—	$	58
Defined Benefit Plan Assets Measured at Fair Value Using Unobservable Inputs (Level Three)	'
	The reconciliation of United’s defined benefit plan assets measured at fair value using unobservable inputs (Level 3) for the years ended December 31, 2013 and 2012 is as follows (in millions):
		2013			2012
	Balance at beginning of year	$	256		$	249
	Actual return on plan assets:
	Sold during the year		15			—
	Held at year end		7			-47
	Purchases, sales, issuances and settlements (net)		15			54
	Balance at end of year	$	293		$	256
Estimated Future Benefit Payments	'
	The estimated future benefit payments, net of expected participant contributions, in United’s pension plans and other postretirement benefit plans as of December 31, 2013 are as follows (in millions):
		Pension			Other			Other Postretirement—
					Postretirement			subsidy receipts
	2014	$	247		$	122		$	6
	2015		259			123			7
	2016		265			126			7
	2017		271			129			8
	2018		268			132			9
	Years 2019 – 2023		1,435			717			53
Multi-Employer Plans	'
	Pension Fund	IAM National Pension Fund
	EIN/ Pension Plan Number	51-6031295 - 002
	Pension Protection Act Zone Status (2013 and 2012)*	Green Zone
	FIP/RP Status Pending/Implemented	No
	United’s Contributions	$38 million, $36 million and $34 million in the years ended December 31, 2013, 2012 and 2011, respectively
	Surcharge Imposed	No
	Expiration Date of Collective Bargaining Agreement	N/A
	* Plans in the green zone are at least 80 percent funded.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The table below presents disclosures about the fair value of financial assets and financial liabilities measured at fair value on a recurring basis in the Company’s financial statements as of December 31 (in millions):
		2013										2012
		Total			Level 1			Level 2		Level 3		Total		Level 1		Level 2		Level 3
		UAL
	Cash and cash equivalents	$	3,220		$	3,220		$	—	$	—	$	4,770	$	4,770	$	—	$	—
	Short-term investments:
	Asset-backed securities		694			—			694		—		715		—		715		—
	Corporate debt		685			—			685		—		537		—		537		—
	Certificates of deposit placed through an account registry service (“CDARS”)		301			—			301		—		367		—		367		—
	Auction rate securities		105			—			—		105		116		—		—		116
	U.S. government and agency notes		38			—			38		—		12		—		12		—
	Other fixed income securities		78			—			78		—		26		—		26		—
	Enhanced equipment trust certificates (“EETC”)		61			—			—		61		63		—		—		63
	Fuel derivatives, net		104			—			104		—		46		—		46		—
	Foreign currency derivatives		1			—			1		—		—		—		—		—
	Restricted cash		395			395			—		—		447		447		—		—
		United
	Cash and cash equivalents	$	3,214		$	3,214		$	—	$	—	$	4,765	$	4,765	$	—	$	—
	Short-term investments:
	Asset-backed securities		694			—			694		—		715		—		715		—
	Corporate debt		685			—			685		—		537		—		537		—
	CDARS		301			—			301		—		367		—		367		—
	Auction rate securities		105			—			—		105		116		—		—		116
	U.S. government and agency notes		38			—			38		—		12		—		12		—
	Other fixed income securities		78			—			78		—		26		—		26		—
	EETC		61			—			—		61		63		—		—		63
	Fuel derivatives, net		104			—			104		—		46		—		46		—
	Foreign currency derivatives		1			—			1		—		—		—		—		—
	Restricted cash		395			395			—		—		447		447		—		—
	Convertible debt derivative asset		480			—			—		480		268		—		—		268
	Convertible debt option liability		-270			—			—		-270		-128		—		—		-128
Activity for "Level Three" Financial Assets and Financial Liabilities	'
	The tables below present disclosures about the activity for “Level 3” financial assets and financial liabilities for the year ended December 31 (in millions):
		2013										2012
		UAL and United						United				UAL and United				United
		Student			EETC			Convertible		Convertible		Student		EETC		Convertible		Convertible
		Loan-Related						Debt		Debt		Loan-Related				Debt		Debt
		Auction Rate						Supplemental		Conversion		Auction Rate				Supplemental		Conversion
		Securities						Derivative		Option		Securities				Derivative		Option
								Asset		Liability						Asset		Liability
	Balance at January 1	$	116		$	63		$	268	$	-128	$	113	$	60	$	193	$	-95
	Purchases, (sales), issuances and settlements (net)		-19			-4			—		—		—		-5		—		—
	Gains and (losses):
	Reported in earnings:
	Realized		3			—			—		—		—		—		—		—
	Unrealized		1			—			212		-142		1		—		75		-33
	Reported in other comprehensive income (loss)		4			2			—		—		2		8		—		—
	Balance at December 31	$	105		$	61		$	480	$	-270	$	116	$	63	$	268	$	-128
Carrying Values and Estimated Fair Values of Financial Instruments	'
	The table below presents the carrying values and estimated fair values of financial instruments not presented in the tables above for the years ended December 31 (in millions):
		Fair Value of Debt by Fair Value Hierarchy Level
		2013												2012
		Carrying			Fair Value									Carrying		Fair Value
		Amount												Amount
					Total			Level 1		Level 2		Level 3				Total		Level 1		Level 2		Level 3
	UAL debt	$	11,539		$	12,695		$	—	$	8,829	$	3,866	$	12,252	$	13,419	$	—	$	8,045	$	5,374
	United debt		11,388			12,249			—		8,383		3,866		11,850		12,460		—		7,086		5,374
Fair Value Methodology for Company Financial Instruments	'
	Fair value of the Company’s financial instruments was determined as follows:
	Description	Fair Value Methodology
	Cash and cash equivalents	The carrying amounts approximate fair value because of the short-term maturity of these assets.
	Short-term investments and Restricted cash	Fair value is based on (a) the trading prices of the investment or similar instruments, (b) an income approach, which uses valuation techniques to convert future amounts into a single present amount based on current market expectations about those future amounts when observable trading prices are not available, (c) internally-developed models of the expected future cash flows related to the securities, or (d) broker quotes obtained by third-party valuation services.
	Fuel derivatives	Derivative contracts are privately negotiated contracts and are not exchange traded. Fair value measurements are estimated with option pricing models that employ observable inputs. Inputs to the valuation models include contractual terms, market prices, yield curves, fuel price curves and measures of volatility, among others.
	Foreign currency derivatives	Fair value is determined with a formula utilizing observable inputs. Significant inputs to the valuation models include contractual terms, risk-free interest rates and forward exchange rates.
	Debt	Fair values were based on either market prices or the discounted amount of future cash flows using our current incremental rate of borrowing for similar liabilities.
	Convertible debt derivative asset and option liability	United used a binomial lattice model to value the conversion options and the supplemental derivative assets. Significant binomial model inputs that are not objectively determinable include volatility and the Company’s credit risk component of the discount rate.
Level 3	'
Fair Value Methodology for Company Financial Instruments	'
	Quantitative Information About Level 3 Fair Value Measurements as of December 31, 2013 ($ in millions)
	Item	Fair Value at			Valuation Technique		Unobservable Input	Range
		December 31, 2013						(Weighted Average)
	Auction rate securities	$	105		Valuation Service / Broker Quotes		Broker quotes (a)	NA
	EETC		61		Discounted Cash Flows		Structure credit risk (b)	4% - 5% (4%)
	Convertible debt		480		Binomial Lattice Model		Expected volatility (c)	45% - 60% (46%)
	derivative asset						Own credit risk (d)	-5%
	Convertible debt		(270	)	Binomial Lattice Model		Expected volatility (c)	45% - 60% (47%)
	option liability						Own credit risk (d)	-5%
	(a) Broker quotes obtained by a third-party valuation service.
	(b) Represents the credit risk premium of the EETC structure above the risk-free rate that the Company has determined market participants would use in pricing the instruments.
	(c) Represents the range in volatility estimates that the Company has determined market participants would use when pricing the instruments.
	(d) Represents the range of Company-specific risk adjustments that the Company has determined market participants would use as a model input.

Hedging_Activities_Tables

Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2013
Description of Derivative Instruments	'
	At December 31, the Company’s derivatives were reported in its consolidated balance sheets as follows (in millions):
	Classification	Balance Sheet Location		2013				2012
	Derivatives designated as cash flow hedges
	Assets:
	Fuel contracts due within one year	Receivables		$	19			$	7
	Fuel contracts with maturities greater than one year	Other assets: Other, net			6				—
	Total assets			$	25			$	7
	Liabilities:
	Fuel contracts due within one year	Current liabilities: Other		$	—			$	2
	Derivatives not designated for hedge accounting
	Assets:
	Fuel contracts due within one year	Receivables		$	70			$	44
	Fuel contracts with maturities greater than one year	Other assets: Other, net			9				—
	Total assets			$	79			$	44
	Liabilities:
	Fuel contracts due within one year	Current liabilities: Other		$	—			$	2
	Fuel contracts with maturities greater than one year	Other liabilities and deferred credits: Other			—				1
	Total liabilities			$	—			$	3
	Total derivatives
	Assets:
	Fuel contracts due within one year	Receivables		$	89			$	51
	Fuel contracts with maturities greater than one year	Other assets: Other, net			15				—
	Total assets			$	104			$	51
	Liabilities:
	Fuel contracts due within one year	Current liabilities: Other		$	—			$	4
	Fuel contracts with maturities greater than one year	Other liabilities and deferred credits: Other			—				1
	Total liabilities			$	—			$	5
Offsetting Assets and Liabilities	'
	The following table shows the potential net fair value positions had we elected to offset. The table reflects offset at the counterparty level (in millions):
		Receivables				Other assets:				Hedge
						Other, net				Derivatives,
										Net
	2013	$	89			$	15			$	104
	2012		46				—				46
Schedule of Gains (Losses) on Derivative Instruments	'
	The following tables present the fuel hedge gains (losses) recognized during the periods presented and their classification in the financial statements (in millions):
	Derivatives designated as cash flow hedges
		Amount of Gain (Loss)								Gain (Loss)				Amount of Gain (Loss)
		Recognized								Reclassified from				Recognized in
		in AOCI on Derivatives								AOCI into Income				Nonoperating income
		(Effective Portion)								(Fuel Expense)				(expense):  Miscellaneous, net
										(Effective Portion)				(Ineffective Portion)
		2013				2012				2013		2012		2013		2012
	Fuel contracts	$	39			$	-51			$	18	$	-141	$	5	$	-1
Schedule of Derivative Instruments not Designated as Hedges Gains (Losses)	'
	Derivatives not designated for hedge accounting
		Amount of Gain Recognized
		in Nonoperating income  (expense):
		Miscellaneous, net
		2013				2012				2011
	Fuel contracts	$	79			$	38			$	—
Schedule of Derivative Credit Risk and Fair Value	'
	The following table presents information related to the Company’s derivative credit risk as of December 31 (in millions):
		2013				2012
	Net derivative assets with counterparties	$	104			$	46
	Collateral held by the Company (classified as an other current liability)		—				—
	Potential loss related to the failure of the Company’s counterparties to perform		104				46

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt	'
	(In millions)	At December 31,
		2013				2012
	United:
	Secured
	Notes payable, fixed interest rates of 4.00% to 12.00% (weighted average rate of 6.50% as of December 31, 2013), payable through 2025	$	6,279			$	5,943
	Notes payable, floating interest rates of the London Interbank Offered Rate (“LIBOR”) plus 0.20% to 5.46%, payable through 2025		1,243				1,668
	Term loan, LIBOR subject to a 1% floor, plus 3%, or alternative rate based on certain market rates plus 2%, due 2019		893				—
	Amended credit facility, LIBOR plus 2.0%, due 2014		—				1,201
	6.75% senior secured notes due 2015		800				800
	9.875% senior secured notes and 12% second lien due 2013		—				600
	Unsecured
	4.5% senior limited subordination convertible notes due 2021		156				156
	6% notes due 2026 to 2028		652				652
	6% senior notes due 2020		300				—
	6% convertible junior subordinated debentures due 2030		248				248
	6.375% senior notes due 2018		300				—
	8% notes due 2024		400				400
	4.5% convertible notes due 2015		230				230
	Other		103				161
			11,604				12,059
	Less: unamortized debt discount		-169				-152
	Less: current portion of long-term debt—United		-1,368				-1,812
	Long-term debt, net—United (a)	$	10,067			$	10,095
	UAL:
	6% convertible senior notes due 2029	$	104			$	345
	Long-term debt, net—UAL	$	10,171			$	10,440
	(a) As further described below under “Convertible Debt Securities and Derivatives,” there is a basis difference between UAL and United debt values, because we were required to apply different accounting methodologies. The United debt presented above does not agree to United’s balance sheet by the amount of this adjustment.
Contractual Principal Payments	'
	The table below presents the Company’s contractual principal payments at December 31, 2013 under then-outstanding long-term debt agreements in each of the next five calendar years (in millions):
		UAL				United
	2014	$	1,368			$	1,368
	2015		2,072				2,072
	2016		1,051				1,051
	2017		614				614
	2018		1,135				1,135
	After 2018		5,468				5,364
		$	11,708			$	11,604
Details of Pass Through Trusts	'
	Certain details of the pass-through trusts are as follows (in millions, except interest rate):
	EETC Date	Class		Principal				Final	Stated		Total debt		Proceeds		Remaining
								expected	interest		recorded		received from		proceeds from
								distribution	rate		as of December 31,		issuance of		issuance of debt
								date			2013		debt during		to be received
													2013		in future
															periods
	Aug-13	A		$	720			August 2025		4.30%	$	153	$	153	$	567
	Aug-13	B			209			Aug-21		5.38%		44		44		165
	Dec-12	C			425			Apr-18		6.13%		425		147		—
	Oct-12	A			712			October 2024		4.00%		712		465		—
	Oct-12	B			132			Oct-20		5.50%		132		86		—
				$	2,198						$	1,466	$	895	$	732
Summary of Collateral Covenants and Cross Default Provisions	'
	The collateral, covenants and cross default provisions of the Company’s principal debt instruments that contain such provisions are summarized in the table below:
	Debt Instrument	Collateral, Covenants and Cross Default Provisions
	Credit Agreement	Secured by certain of United’s international route authorities, specified take-off and landing slots at certain airports and certain other assets.
		The Credit Agreement requires the Company to maintain at least $3.0 billion of unrestricted liquidity at all times, which includes unrestricted cash, short-term investments and any undrawn amounts under any revolving credit facility and to maintain a minimum ratio of appraised value of collateral to the outstanding obligations under the Credit Agreement of 1.67 to 1.0 at all times. The Credit Agreement contains covenants that, among other things, restrict the ability of UAL and its restricted subsidiaries (as defined in the Credit Agreement) to incur additional indebtedness and to pay dividends on or repurchase stock.
		The Credit Agreement contains events of default customary for this type of financing, including a cross default and cross acceleration provision to certain other material indebtedness of the Company.
	6% Notes due 2026	The amended and restated indenture for these notes, which are unsecured, contains covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indenture) to incur additional indebtedness and pay dividends on or repurchase stock.
	6% Notes due 2028	These covenants cease to be in effect when the indenture covering the 6.375% Senior Notes due 2018 is discharged.
		The indenture contains events of default that are customary for similar financings.
	6.375% Senior Notes due 2018	The indentures for these notes, which are unsecured, contain covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indenture) to incur additional indebtedness and pay dividends on or repurchase stock.
	6% Senior Notes due 2020	The indentures contain events of default that are customary for similar financings.
	6.75% Senior Notes due 2015	Secured by certain of United’s U.S.-Asia and U.S.-London Heathrow routes and related assets, all of the outstanding common stock and other assets of Air Micronesia, Inc. (“AMI”) and Continental Micronesia, Inc. (“CMI”) and substantially all of the other assets of AMI and CMI, including route authorities and related assets.
		The indenture for these notes includes covenants that, among other things, restrict United’s ability to sell assets, incur additional indebtedness, issue preferred stock, make investments and pay dividends on or repurchase stock. In addition, if United fails to maintain a collateral coverage ratio of 1.5 to 1.0, United must pay additional interest on the Senior Notes at the rate of 2% per annum until the collateral coverage ratio equals at least 1.5 to 1.0.
		The indenture for these notes also includes events of default customary for similar financings and a cross default provision if United fails to make payment when due with respect to certain obligations regarding frequent flyer miles purchased by Chase under United’s Co-Brand Agreement.

Leases_and_Capacity_Purchase_A1

Leases and Capacity Purchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2013
Future Minimum Lease Payments for Capital and Operating Leases	'
	At December 31, 2013, United’s scheduled future minimum lease payments under operating leases having initial or remaining noncancelable lease terms of more than one year, aircraft leases, including aircraft rent under CPAs and capital leases (substantially all of which are for aircraft) were as follows (in millions):
		Capital Leases (a)		Facility and Other		Aircraft Operating
				Operating Leases		Leases (b)
	2014	$	206	$	1,192	$	1,601
	2015		183		987		1,381
	2016		168		864		1,150
	2017		123		831		1,053
	2018		106		710		786
	After 2018		678		6,002		1,819
	Minimum lease payments	$	1,464	$	10,586	$	7,790
	Imputed interest		-594
	Present value of minimum lease payments		870
	Current portion		-117
	Long-term obligations under capital leases	$	753
	(a) As of December 31, 2013, United’s aircraft capital lease minimum payments relate to leases of 47 mainline and 38 regional aircraft as well as to leases of nonaircraft assets. Imputed interest rate ranges are 4.8% to 18.5%.
	(b) The operating lease payments presented above include future payments of $103 million related to 25 nonoperating aircraft as of December 31, 2013.
Future Lease Payment Under Terms of Capacity Purchase Agreement	'
	Based on these assumptions as of December 31, 2013, our future payments through the end of the terms of our CPAs are presented in the table below (in millions):
	2014	$	1,936
	2015		1,747
	2016		1,532
	2017		1,449
	2018		1,340
	After 2018		3,410
		$	11,414

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Firm Commitments to Purchase Aircraft	'
	As of December 31, 2013, United had firm commitments to purchase aircraft from The Boeing Company (“Boeing”), Embraer and Airbus S.A.S. (“Airbus”) presented in the table below:
	Aircraft Type	Number of Firm
		Commitments (a)
	Airbus A350-1000		35
	Boeing 737-900ER		63
	Boeing 737 MAX 9		100
	Boeing 787-8/-9/-10		57
	Embraer EMB175		30
	(a) United also has options and purchase rights for additional aircraft.
Schedule of Acquisition of Aircrafts and Related Spare Engines	'
	The table below summarizes United’s commitments as of December 31, 2013 (including those assigned from UAL), which primarily relate to the acquisition of aircraft and related spare engines, aircraft improvements and include other commitments primarily to acquire information technology services and assets for the years ended December 31 (in billions):
	2014	$	3.0
	2015		2.8
	2016		2.0
	2017		1.5
	2018		2.1
	After 2018		12.5
		$	23.9

Statement_of_Consolidated_Cash1

Statement of Consolidated Cash Flows - Supplemental Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Supplemental Disclosures of Cash Flow Information and Non-Cash Investing and Financing Activities	'
	Supplemental disclosures of cash flow information and non-cash investing and financing activities for the years ended December 31 are as follows (in millions):
	2013	UAL		United
	Cash paid (refunded) during the period for:
	Interest (net of amounts capitalized)	$	752	$	752
	Income taxes		-20		-15
	Non-cash transactions:
	Net property and equipment acquired through issuance of debt	$	229	$	229
	Airport construction financing		40		40
	Exchanges of certain 6% convertible senior notes for common stock		240		—
	2012
	Cash paid during the period for:
	Interest (net of amounts capitalized)	$	766	$	766
	Income taxes		2		4
	Non-cash transactions:
	Net property and equipment acquired through issuance of debt	$	544	$	544
	8% Contingent Senior Unsecured Notes and 6% Senior Notes, net of discount		357		357
	Special facility payment financing		101		101
	Airport construction financing		50		50
	2011
	Cash paid during the period for:
	Interest (net of amounts capitalized)	$	855	$	855
	Income taxes		10		2
	Non-cash transactions:
	Net property and equipment acquired through issuance of debt	$	130	$	130
	8% Contingent Senior Unsecured Notes, net of discount		88		88
	Interest paid in kind on 6% Senior Notes		37		37

IntegrationRelated_Costs_and_S1

Integration-Related Costs and Special Items (Tables)	12 Months Ended
	Dec. 31, 2013
Components of Integration-Related Costs and Special Items	'
	Integration-related costs and special items classified as special charges in the statements of consolidated operations consisted of the following for the years ended December 31 (in millions):
		2013			2012			2011
	Integration-related costs	$	205		$	739		$	517
	Labor agreement costs		127			475			—
	Severance and benefits		105			125			—
	Asset impairments		33			30			4
	Termination of maintenance service contract		—			—			58
	Additional costs associated with the temporarily grounded Boeing 787 aircraft		18			—			—
	(Gains) losses on sale of assets and other special charges, net		32			-46			13
	Total	$	520		$	1,323		$	592
Accrual Activity	'
	Activity related to the accruals for severance and medical costs and future lease payments on permanently grounded aircraft is as follows (in millions):
		Severance/			Permanently
		Medical Costs			Grounded Aircraft
	Balance at December 31, 2010	$	102		$	41
	Accrual		21			5
	Payments		(68	)		(15	)
	Balance at December 31, 2011		55			31
	Accrual		170			(1	)
	Payments		(160	)		(25	)
	Balance at December 31, 2012		65			5
	Accrual		120			10
	Payments		(94	)		(4	)
	Balance at December 31, 2013	$	91		$	11

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2013
Operating Revenue by Principle Geographic Region	'
	The Company’s operating revenue by principal geographic region (as defined by the U.S. Department of Transportation) for the years ended December 31 is presented in the table below (in millions):
	2013	UAL		United
	Domestic (U.S. and Canada)	$	22,092	$	22,100
	Pacific		5,794		5,794
	Atlantic		7,132		7,132
	Latin America		3,261		3,261
	Total	$	38,279	$	38,287
	2012
	Domestic (U.S. and Canada)	$	21,276	$	21,284
	Pacific		6,040		6,040
	Atlantic		6,582		6,582
	Latin America		3,254		3,254
	Total	$	37,152	$	37,160
	2011
	Domestic (U.S. and Canada)	$	21,922	$	21,931
	Pacific		5,404		5,404
	Atlantic		6,675		6,675
	Latin America		3,109		3,109
	Total	$	37,110	$	37,119

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Schedule of Selected Quarterly Financial Data	'
	UAL	Quarter Ended
	(In millions, except per share amounts)	March 31		June 30		September 30		December 31
	2013
	Operating revenue	$	8,721	$	10,001	$	10,228	$	9,329
	Income (loss) from operations		-264		770		508		235
	Net income (loss)		-417		469		379		140
	Basic earnings (loss) per share		-1.26		1.37		1.06		0.39
	Diluted earnings (loss) per share		-1.26		1.21		0.98		0.37
	2012
	Operating revenue	$	8,602	$	9,939	$	9,909	$	8,702
	Income (loss) from operations		-271		575		200		-465
	Net income (loss)		-448		339		6		-620
	Basic earnings (loss) per share		-1.36		1.02		0.02		-1.87
	Diluted earnings (loss) per share		-1.36		0.89		0.02		-1.87
Schedule of Effect of Four Quarters Events	'
	UAL’s quarterly results were impacted by the following significant items (in millions):
		Quarter Ended
		March 31		June 30		September 30		December 31
	2013
	Special charges (income):
	Integration-related costs	$	70	$	45	$	50	$	40
	Labor agreement costs		—		—		127		—
	Severance and benefits		14		—		—		91
	Asset impairments		—		—		—		33
	Additional costs associated with the temporarily grounded Boeing 787 aircraft		11		7		—		—
	(Gains) losses on sale of assets and other special charges, net		-3		—		34		1
	Total special items		92		52		211		165
	Income tax benefit		—		—		—		-7
	Total special items, net of tax	$	92	$	52	$	211	$	158
	2012
	Special charges (income):
	Integration-related costs	$	134	$	137	$	60	$	408
	Labor agreement costs		—		—		454		21
	Severance and benefits		49		76		—		—
	Asset impairments		6		—		—		24
	Gains on sale of assets and other special charges, net		-25		-7		—		-14
	Total special items		164		206		514		439
	Income tax benefit		-2		—		—		-9
	Total special items, net of tax	$	162	$	206	$	514	$	430

Significant_Accounting_Policie3

Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended					1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2013	Jun. 09, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2013
				Minimum	United Airlines, Inc.	Co-Brand Agreement	Computer software	Computer software	Computer software	Aircraft and related rotable parts	Aircraft and related rotable parts
						Item				Minimum	Maximum
Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Refundable tickets expiration period	'	'	'	'1 year	'	'	'	'	'	'	'
Number of elements identified in agreement	'	'	'	'	'	5	'	'	'	'	'
Carrying value of computer software	$290	$302	'	'	'	'	'	'	'	'	'
Depreciation expense related to computer software	'	'	'	'	'	'	72	81	133	'	'
Residual values	'	'	'	'	'	'	'	'	'	10.00%	11.00%
Advertising expense	178	154	142	'	'	'	'	'	'	'	'
Receivable from related parties	'	'	'	'	$232	'	'	'	'	'	'

Schedule_of_Information_Relate

Schedule of Information Related to Amounts Recorded Related to Frequent Flyer Program (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Significant Accounting Policies [Line Items]	'		'		'
Cash Proceeds from Miles Sold	$2,903		$2,852		$3,121
Other Revenue Recognized Upon Award of Miles to Third-Party Customers	903	[1]	816	[1]	566	[1]
Increase in Frequent Flyer Deferred Revenue for Miles Awarded	2,174	[2]	2,036	[2]	2,357	[2]
Increase (Decrease) in Advanced Purchase of Miles	($174)	[3]	'		$198	[3]
[1]	This amount represents other revenue recognized during the period from the sale of miles to third parties, representing the marketing-related deliverable services component of the sale.
[2]	This amount represents the increase to frequent flyer deferred revenue during the period.
[3]	This amount represents the net increase (decrease) in the advance purchase of miles obligation due to cash payments for the sale of miles in excess of (less than) miles awarded to customers.

Estimated_Useful_Lives_of_Prop

Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2013
Aircraft and related rotable parts | Minimum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'25 years
Aircraft and related rotable parts | Maximum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'30 years
Buildings | Minimum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'25 years
Buildings | Maximum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'45 years
Other property and equipment | Minimum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'4 years
Other property and equipment | Maximum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'15 years
Computer software	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'5 years
Building improvements | Minimum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'1 year
Building improvements | Maximum	'
Property, Plant and Equipment [Line Items]	'
Estimated Useful Life	'40 years

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Goodwill And Intangible Assets [Line Items]	'		'
Goodwill	$4,523		$4,523
Finite-lived intangible assets, Gross Carrying Amount	1,804		1,805
Finite-lived intangible assets, Accumulated Amortization	933		792
Indefinite-lived intangible assets, Gross Carrying Amount	3,565		3,584
Hubs	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Asset life	'20 years	[1]	'
Finite-lived intangible assets, Gross Carrying Amount	145		145
Finite-lived intangible assets, Accumulated Amortization	59		52
Patents And Trade Names	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Asset life	'3 years	[1]	'
Finite-lived intangible assets, Gross Carrying Amount	108		108
Finite-lived intangible assets, Accumulated Amortization	108		99
Frequent Flyer Database	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Asset life	'22 years	[1],[2]	'
Finite-lived intangible assets, Gross Carrying Amount	1,177	[2]	1,177	[2]
Finite-lived intangible assets, Accumulated Amortization	536	[2]	447	[2]
Contracts	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Asset life	'13 years	[1]	'
Finite-lived intangible assets, Gross Carrying Amount	167		167
Finite-lived intangible assets, Accumulated Amortization	86		75
Other Intangible Assets	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Asset life	'25 years	[1]	'
Finite-lived intangible assets, Gross Carrying Amount	109		109
Finite-lived intangible assets, Accumulated Amortization	56		44
Route Authorities	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Indefinite-lived intangible assets, Gross Carrying Amount	1,605		1,606
Tradenames And Logos	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Indefinite-lived intangible assets, Gross Carrying Amount	593		593
Alliances	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Indefinite-lived intangible assets, Gross Carrying Amount	404		404
Airport Slots And Gates	'		'
Goodwill And Intangible Assets [Line Items]	'		'
Asset life	'8 years	[1]	'
Finite-lived intangible assets, Gross Carrying Amount	98		99
Finite-lived intangible assets, Accumulated Amortization	88		75
Indefinite-lived intangible assets, Gross Carrying Amount	$963		$981
[1]	Weighted average life expressed in years.
[2]	The frequent flyer database is amortized based on an accelerated amortization schedule to reflect utilization of the assets. Estimated cash flows correlating to the expected attrition rate of customers in the frequent flyer database is considered in the determination of the amortization schedules.

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Actual and Estimated Amortization Expense [Line Items]	'	'	'
Actual amortization	$142	$121	$169
Projected amortization in 2014	128	'	'
Projected amortization in 2015	106	'	'
Projected amortization in 2016	92	'	'
Projected amortization in 2017	81	'	'
Projected amortization in 2018	$72	'	'

Common_Stockholders_Equity_and1

Common Stockholders' Equity and Preferred Securities - Additional Information (Detail) (USD $)	Dec. 31, 2013	Nov. 30, 2013	Jun. 30, 2011	Feb. 20, 2014
In Millions, except Share data, unless otherwise specified		Unsecured Debt	United Airlines, Inc.	Subsequent Event
			Unsecured Debt	United Airlines, Inc.
				Unsecured Debt
Schedule Of Stockholders Equity [Line Items]	'	'	'	'
Common stock reserved for future issuance	44,000,000	'	'	'
Junior preferred stock outstanding	2	'	'	'
Junior preferred stock par value per share	$0.01	'	'	'
Preferred stock authorized to issue	250,000,000	'	'	'
Debt instument converted amount	'	'	'	$156
Debt instrument stated interest rate	'	6.00%	4.50%	4.50%
Debt instrument, maturity date	'	'	'	'2021
Debt instument convertion rate	'	'	'	30.6419

Computation_of_Earnings_Per_Sh

Computation of Earnings Per Share (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Basic earnings (loss) per share:	'	'	'	'	'	'	'	'	'	'	'
Net income (loss)	$140	$379	$469	($417)	($620)	$6	$339	($448)	$571	($723)	$840
Less: Income allocable to participating securities	'	'	'	'	'	'	'	'	-2	'	-3
Earnings (loss) available to common stockholders	'	'	'	'	'	'	'	'	569	-723	837
Basic weighted-average shares outstanding	'	'	'	'	'	'	'	'	348	331	329
Earnings (loss) per share, basic	$0.39	$1.06	$1.37	($1.26)	($1.87)	$0.02	$1.02	($1.36)	$1.64	($2.18)	$2.54
Diluted earnings (loss) per share:	'	'	'	'	'	'	'	'	'	'	'
Earnings (loss) available to common stockholders	'	'	'	'	'	'	'	'	569	-723	837
Effect of dilutive securities	'	'	'	'	'	'	'	'	26	'	27
Earnings (loss) available to common stockholders including the effect of dilutive securities	'	'	'	'	'	'	'	'	$595	($723)	$864
Diluted shares outstanding:	'	'	'	'	'	'	'	'	'	'	'
Basic weighted-average shares outstanding	'	'	'	'	'	'	'	'	348	331	329
Effect of convertible notes	'	'	'	'	'	'	'	'	42	'	52
Effect of employee stock options	'	'	'	'	'	'	'	'	'	'	2
Diluted weighted-average shares outstanding	'	'	'	'	'	'	'	'	390	331	383
Earnings (loss) per share, diluted	$0.37	$0.98	$1.21	($1.26)	($1.87)	$0.02	$0.89	($1.36)	$1.53	($2.18)	$2.26
Potentially dilutive shares excluded from diluted per share amounts:	'	'	'	'	'	'	'	'	'	'	'
Potentially dilutive shares excluded from diluted per share amounts	'	'	'	'	'	'	'	'	7	66	21
Restricted Stock And Stock Options	'	'	'	'	'	'	'	'	'	'	'
Potentially dilutive shares excluded from diluted per share amounts:	'	'	'	'	'	'	'	'	'	'	'
Potentially dilutive shares excluded from diluted per share amounts	'	'	'	'	'	'	'	'	3	5	6
Convertible Notes	'	'	'	'	'	'	'	'	'	'	'
Potentially dilutive shares excluded from diluted per share amounts:	'	'	'	'	'	'	'	'	'	'	'
Potentially dilutive shares excluded from diluted per share amounts	'	'	'	'	'	'	'	'	4	61	15

ShareBased_Compensation_Plans_1

Share-Based Compensation Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Number of days used to compute performance period average closing price of restricted stock units	20	'	'
Employee Stock Option	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options, contractual term, years	'10 years	'	'
Employee Stock Option | Minimum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-Based Compensation, vesting period	'3 years	'	'
Employee Stock Option | Maximum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-Based Compensation, vesting period	'4 years	'	'
Management Level Employee Option	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options, contractual term, years	'5 years	'	'
Outside directors	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options, contractual term, years	'10 years	'	'
RSUs	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-Based Compensation, award granted	0.5	'	'
Share-Based Compensation, vesting period	'3 years	'	'
Share-Based Compensation, award granted	2	2	4
Liabilities related to share based payments	$118	'	'
Payment related to share-based liabilities	29	35	57
Equity awards fair value	$22	$27	$7
Restricted Stock	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-Based Compensation, award granted	0.5	'	'
Share-Based Compensation, vesting period	'3 years	'	'
Share-Based Compensation, award granted	1	1	1
Performance Shares	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-Based Compensation, vesting period	'3 years	'	'
Share-Based Compensation, award granted	1.3	'	'
Share-Based Compensation, vesting date	31-Dec-15	'	'

Schedule_of_ShareBased_Compens

Schedule of Share-Based Compensation Plan Cost (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Compensation cost	$100	[1]	$57	[1]	$54	[1]
RSUs	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Compensation cost	88	[1]	37	[1]	18	[1]
Restricted Stock	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Compensation cost	11	[1]	13	[1]	12	[1]
Share-Based Awards Converted To Cash Awards	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Compensation cost	1	[1]	6	[1]	19	[1]
Stock Options	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Compensation cost	'		$1	[1]	$5	[1]
[1]	All compensation cost is recorded to Salaries and related costs, with the exception of $9 million, $9 million and $17 million in 2013, 2012 and 2011, respectively, that was recorded in integration-related costs as a component of special charges.

Schedule_of_ShareBased_Compens1

Schedule of Share-Based Compensation Plan Cost (Parenthetical) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Integration related costs	$40	$50	$45	$70	$408	$60	$137	$134	$205	$739	$517
Special Charges	'	'	'	'	'	'	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Integration related costs	'	'	'	'	'	'	'	'	$9	$9	$17

Schedule_of_Unearned_Compensat

Schedule of Unearned Compensation and Weighted Average Remaining Period for Outstanding Share-Based Awards (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Unearned Compensation	$44
RSUs	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Unearned Compensation	36
Weighted- Average Remaining Period (in years)	'1 year 3 months 18 days
Restricted Stock	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Unearned Compensation	$8
Weighted- Average Remaining Period (in years)	'1 year 4 months 24 days
Employee Stock Option	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Weighted- Average Remaining Period (in years)	'7 months 6 days

Schedule_of_Restricted_Stock_U

Schedule of Restricted Stock Unit and Restricted Stock Activity (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
RSUs	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Non-vested at beginning of year	4	3	'
Granted, Stock	2	2	4
Vested, Stock	-1	'	'
Surrendered, Stock	'	-1	-1
Non-vested at end of year, Stock	5	4	3
Restricted Stock	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Non-vested at beginning of year	1	1	1
Granted, Stock	1	1	1
Vested, Stock	-1	-1	-1
Non-vested at end of year, Stock	1	1	1
Weighted- Average Grant Price at beginning of year	23.94	23.33	17.2
Granted, Weighted- Average Grant Price	25.98	24.01	23.87
Vested, Weighted- Average Grant Price	23.93	23.05	22.26
Surrendered, Weighted- Average Grant Price	24.76	24.01	23.95
Non-vested at end of year, Weighted- Average Grant Price	25.02	23.94	23.33

Stock_Option_Activity_Detail

Stock Option Activity (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Options, Outstanding at beginning of year	5	7	11
Exercised, Options	-2	-1	-2
Surrendered, Options	'	-1	-2
Options, Outstanding at end of year	3	5	7
Weighted- Average Exercise Price, Outstanding at beginning of year	$25.60	$23.80	$21.70
Exercisable at end of period, Options	3	'	'
Exercised, Weighted- Average Exercise Price	$16.28	$12.42	$10.77
Surrendered, Weighted- Average Exercise Price	$27.49	$30.50	$29.07
Weighted- Average Exercise Price, Outstanding at end of year	$31.63	$25.60	$23.80
Exercisable at end of period, Weighted- Average Exercise Price	$32	'	'
Weighted- Average Remaining Contractual Life , Outstanding at end of year, in years	'2 years 2 months 12 days	'	'
Weighted- Average Remaining Contractual Life , exercisable at end of year, in years	'2 years 2 months 12 days	'	'
Exercised, Aggregate Intrinsic Value	$27	$14	$33
Aggregate Intrinsic Value, Outstanding at end of period	18	'	'
Aggregate Intrinsic Value , Exercisable at end of period	$16	'	'

Components_of_Accumulated_Othe

Components of Accumulated Other Comprehensive Income (Loss), Net of Tax (Detail) (USD $)

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2010

Pension and Other Postretirement Unrecognized Actuarial Gains (Losses) and Prior Service Cost

Pension and Other Postretirement Unrecognized Actuarial Gains (Losses) and Prior Service Cost

Pension and Other Postretirement Unrecognized Actuarial Gains (Losses) and Prior Service Cost

Unrealized Gains (Losses) on Derivatives

Unrealized Gains (Losses) on Derivatives

Unrealized Gains (Losses) on Derivatives

Other

Other

Other

Accumulated Other Comprehensive Income (Loss) [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

($1,046)

[1]

($417)

[1]

$387

[1]

($1,042)

[1]

($312)

[1]

$152

[1]

($10)

[1]

($100)

[1]

$240

[1]

$6

[1]

($5)

[1]

($5)

[1]

Other comprehensive income (loss) before reclassifications

1,630

[1]

-787

[1]

-277

[1]

1,584

[1],[2]

-747

[1]

-440

[1]

39

[1]

-51

[1]

163

[1]

7

[1]

11

[1]

'

Amounts reclassified from accumulated other comprehensive income

24

[1]

158

[1]

-527

[1]

42

[1]

17

[1]

-24

[1]

-18

[1]

141

[1]

-503

[1]

'

'

'

Comprehensive income (loss) adjustments

1,654

[1]

-629

[1]

-804

[1]

1,626

[1]

-730

[1]

-464

[1]

21

[1]

90

[1]

-340

[1]

7

[1]

11

[1]

'

Ending Balance

$608

[1]

($1,046)

[1]

($417)

[1]

$584

[1]

($1,042)

[1]

($312)

[1]

$11

[1]

($10)

[1]

($100)

[1]

$13

[1]

$6

[1]

($5)

[1]

[1]

UAL and United amounts are substantially the same except for an additional $6 million of income tax benefit at United in 2013. In addition, United had additional (losses) gains related to investments and other of $(2) million, $1 million and $1 million in 2011, 2012 and 2013, respectively.

[2]

For 2013, prior service credits increased by $331 million and actuarial gains increased by approximately $1.3 billion. Amounts for 2012 and 2011 were not material.

Details_about_Accumulated_Othe

Details about Accumulated Other Comprehensive Income Components (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Salaries And Related Costs	'		'		'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'		'
Amortization of unrecognized (gains) losses and prior service cost and the effect of curtailments and settlements	$42	[1],[2]	$17	[1],[2]	($24)	[1],[2]
Fuel Oil Contract | Cash Flow Hedging | Aircraft Fuel	'		'		'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'		'
Fuel contracts-reclassifications of (gains) losses into earnings	($18)	[1]	$141	[1]	($503)	[1]
[1]	Income tax expense offset by Company's valuation allowance.
[2]	This accumulated other comprehensive income component is included in the computation of net periodic pension costs (see Note 8 of this report for additional details.)

Components_of_Accumulated_Othe1

Components of Accumulated Other Comprehensive Income (Loss), Net of Tax (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Increase in prior service credits	$331,000,000	'	'
Increase in actuarial gains	1,300,000,000	'	'
United Airlines, Inc.	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Income Tax Expense	6,000,000	'	'
Additional (losses) gains related to investments and other	$1,000,000	$1,000,000	($2,000,000)

Components_of_Income_Tax_Expen

Components of Income Tax Expense (Benefit) (Detail) (USD $)	3 Months Ended			12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components Of Income Tax Expense Benefit [Line Items]	'	'	'	'	'	'
Current	'	'	'	($18)	($14)	$11
Deferred	'	'	'	-14	13	-6
Income tax benefit	-7	-9	-2	-32	-1	5
United Airlines, Inc.	'	'	'	'	'	'
Components Of Income Tax Expense Benefit [Line Items]	'	'	'	'	'	'
Current	'	'	'	-18	-9	3
Deferred	'	'	'	1	13	-5
Income tax benefit	'	'	'	($17)	$4	($2)

Income_Tax_Provision_Differed_

Income Tax Provision Differed from Amounts Computed at Statutory Federal Income Tax Rate (Detail) (USD $)	3 Months Ended			12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]	'	'	'	'	'	'
Income tax provision at statutory rate	'	'	'	$189	($253)	$298
State income taxes, net of federal income tax	'	'	'	5	-15	-19
Foreign income taxes	'	'	'	3	7	'
Nondeductible acquisition costs	'	'	'	'	'	-17
Nondeductible employee meals	'	'	'	15	12	12
Nondeductible interest expense	'	'	'	'	19	13
Nondeductible compensation	'	'	'	3	5	9
State rate change	'	'	'	-33	'	'
Valuation allowance	'	'	'	-219	234	-294
Other, net	'	'	'	5	-10	3
Income tax benefit	-7	-9	-2	-32	-1	5
United Airlines, Inc.	'	'	'	'	'	'
Income Taxes [Line Items]	'	'	'	'	'	'
Income tax provision at statutory rate	'	'	'	223	-230	299
State income taxes, net of federal income tax	'	'	'	5	-7	-17
Foreign income taxes	'	'	'	3	7	'
Nondeductible acquisition costs	'	'	'	'	'	-17
Nondeductible employee meals	'	'	'	15	12	12
Nondeductible interest expense	'	'	'	'	19	13
Derivative market adjustment	'	'	'	-24	-15	10
Nondeductible compensation	'	'	'	3	5	10
State rate change	'	'	'	-33	'	'
Valuation allowance	'	'	'	-229	223	-315
Other, net	'	'	'	20	-10	3
Income tax benefit	'	'	'	($17)	$4	($2)

Components_of_Deferred_Tax_Ass

Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Deferred income tax asset (liability):	'		'
Federal and state net operating loss ("NOL") carryforwards	$3,221		$3,025
Frequent flyer deferred revenue	2,254		2,425
Employee benefits, including pension, postretirement, medical and the Pension Benefit Guaranty Corporation ("PBGC") notes	1,701		2,488
Lease fair value adjustment	123		259
AMT credit carryforwards	233		251
Other assets	217		947
Less: Valuation allowance	-3,806		-4,603
Total deferred tax assets	3,943	[1]	4,792	[1]
Depreciation, capitalized interest and other	-3,201		-3,705
Intangibles	-1,585		-1,578
Other liabilities	-144		-509
Total deferred tax liabilities	-4,930		-5,792
Net deferred tax liability	-987	[1]	-1,000	[1]
United Airlines, Inc.	'		'
Deferred income tax asset (liability):	'		'
Federal and state net operating loss ("NOL") carryforwards	3,158		2,957
Frequent flyer deferred revenue	2,254		2,426
Employee benefits, including pension, postretirement, medical and the Pension Benefit Guaranty Corporation ("PBGC") notes	1,701		2,491
Lease fair value adjustment	123		259
AMT credit carryforwards	233		251
Other assets	217		882
Less: Valuation allowance	-3,776		-4,503
Total deferred tax assets	3,910	[1]	4,763	[1]
Depreciation, capitalized interest and other	-3,201		-3,702
Intangibles	-1,585		-1,579
Other liabilities	-111		-406
Total deferred tax liabilities	-4,897		-5,687
Net deferred tax liability	($987)	[1]	($924)	[1]
[1]	During 2013, UAL identified adjustments to the components of the deferred taxes. As a result of this analysis, changes in deferred tax assets and liabilities occurred, and are reflected in 2013 deferred tax balances. UAL and United increased their valuation allowance to reflect these adjustments by $84 million and $163 million, respectively. United separately identified an adjustment of $68 million to increase its deferred tax liability with an offset to United-only equity to correct an error made in prior years. This item did not affect the consolidated accounts of UAL. It was corrected in the current period as it was not considered material to United's prior year reported financial position.

Components_of_Deferred_Tax_Ass1

Components of Deferred Tax Assets and Liabilities (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Valuation allowance for deferred tax assets	'
Deferred Income Tax Assets And Liabilities [Line Items]	'
Valuation allowance adjustments	$84	[1]
United Airlines, Inc.	'
Deferred Income Tax Assets And Liabilities [Line Items]	'
Tax adjustment	68
United Airlines, Inc. | Valuation allowance for deferred tax assets	'
Deferred Income Tax Assets And Liabilities [Line Items]	'
Valuation allowance adjustments	$163	[1]
[1]	See Note 7 to the financial statements included in Part II, Item 8 of this report for additional information related to other valuation allowance adjustments.

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]	'	'	'	'
Unrecorded tax benefit	$800,000,000	'	'	'
Federal pre-tax NOL carry forwards	10,900,000,000	'	'	'
State tax benefits	168,000,000	'	'	'
Cumulative loss position at the end of 2013	'3 years	'	'	'
Percentage of cumulative pretax income related to revenue	0.60%	'	'	'
Current valuation allowances	3,806,000,000	4,603,000,000	'	'
Increase (decrease) in current valuation allowances	-797,000,000	'	'	'
Unrecognized tax benefits	14,000,000	19,000,000	24,000,000	32,000,000
Unrecognized tax benefits that would impact effective tax rate if recognized	12,000,000	'	'	'
United Airlines, Inc.	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Current valuation allowances	3,776,000,000	4,503,000,000	'	'
Increase (decrease) in current valuation allowances	-727,000,000	'	'	'
2022	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Net operating loss expiration amount	1,400,000,000	'	'	'
2023	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Net operating loss expiration amount	1,900,000,000	'	'	'
2024	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Net operating loss expiration amount	2,400,000,000	'	'	'
2025	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Net operating loss expiration amount	2,000,000,000	'	'	'
Thereafter	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Net operating loss expiration amount	$3,200,000,000	'	'	'
Minimum	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
State tax benefits of the NOL carry forwards expiration period, years	'5 years	'	'	'
Maximum	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
State tax benefits of the NOL carry forwards expiration period, years	'20 years	'	'	'

Reconciliation_of_Unrecognized

Reconciliation of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Contingency [Line Items]	'	'	'
Balance at January 1,	$19	$24	$32
Decrease in unrecognized tax benefits relating to settlements with taxing authorities	'	-12	'
Increase (decrease) in unrecognized tax benefits as a result of tax positions taken during a prior period	'	8	-9
Decrease in unrecognized tax benefits relating from a lapse of the statute of limitations	-5	-1	'
Increase in unrecognized tax benefits as a result of tax positions taken during the current period	'	'	1
Balance at December 31,	$14	$19	$24

Pension_and_Other_Postretireme2

Pension and Other Postretirement Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Y
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pilot retirement age	65	'	'
Effect on post retirement benefit obligation, 1% Decrease	$203	'	'
Effect on total service and interest cost,1% Decrease	10	'	'
Profit sharing and payroll tax expense	190	119	265
Multiemployer Plans, Pension | IAM National Pension Plan	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Multi-employer plan contributions	'	351	'
Minimum	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined benefit plan, service period	'20 years	'	'
Percentage of pre-tax earnings paid for profit sharing plan	5.00%	'	'
Share-based compensation program pre-tax profits excluding special items, profit sharing expense and share-based compensation program expense threshold	10	'	'
Minimum | Multiemployer Plans, Pension | IAM National Pension Plan	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Percent of company's contribution to plan	'	5.00%	'
Maximum	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Percentage of pre-tax earnings paid for profit sharing plan	20.00%	'	'
Other Postretirement Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Effect on post retirement benefit obligation, 1% Decrease	-186	'	'
Effect on total service and interest cost,1% Decrease	-17	'	'
Employer contributions	128	116	'
Other Postretirement Benefits | Deposit Administration Fund	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Target allocation of plan assets	100.00%	'	'
Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contributions	277	228	'
United Airlines, Inc.	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contributions	433	330	291
United Airlines, Inc. | Multiemployer Plans, Pension | IAM National Pension Plan	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Multi-employer plan contributions	38	36	34
United Airlines, Inc. | Minimum	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contribution, percentage	1.00%	'	'
United Airlines, Inc. | Maximum	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contribution, percentage	16.00%	'	'
United Airlines, Inc. | Other Postretirement Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contributions	120	'	'
United Airlines, Inc. | Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contributions	$288	'	'

Reconciliation_of_Change_in_Pr

Reconciliation of Change in Projected Benefit Obligation and Plan Assets (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Balance at end of year	$293	$256	$249
Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Accumulated benefit obligation:	3,383	3,978	'
Benefit obligation at beginning of year	4,526	3,708	'
Service cost	121	99	88
Interest cost	191	184	178
Actuarial (gain) loss	-464	702	'
Gross benefits paid and settlements	-269	-162	'
Curtailments	-84	'	'
Other	-21	-5	'
Benefit obligation at end of year	4,000	4,526	3,708
Balance at beginning of year	2,157	1,868	'
Actual return on plan assets	239	223	'
Employer contributions	277	228	'
Gross benefits paid and settlements	-269	-162	'
Other	-7	'	'
Balance at end of year	2,397	2,157	1,868
Funded status-Net amount recognized	-1,603	-2,369	'
Other Postretirement Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Benefit obligation at beginning of year	2,743	2,541	'
Service cost	52	50	47
Interest cost	110	124	127
Plan participants' contributions	67	77	'
Actuarial (gain) loss	-640	110	'
Federal subsidy	7	13	'
Plan amendments	-331	22	'
Curtailments	8	'	'
Gross benefits paid	-197	-194	'
Benefit obligation at end of year	1,819	2,743	2,541
Balance at beginning of year	58	58	'
Actual return on plan assets	1	1	'
Employer contributions	128	116	'
Plan participants' contributions	67	77	'
Benefits paid	-197	-194	'
Balance at end of year	57	58	58
Funded status-Net amount recognized	($1,762)	($2,685)	'

Amounts_Recognized_in_Consolid

Amounts Recognized in Consolidated Balance Sheet and Accumulated Other Comprehensive Income (Loss) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Pension Benefits	'	'
Amounts recognized in the consolidated balance sheets consist of:	'	'
Noncurrent asset	$49	$35
Current liability	-2	-4
Noncurrent liability	-1,650	-2,400
Total liability	-1,603	-2,369
Amounts recognized in accumulated other comprehensive income (loss) consist of:	'	'
Net actuarial gain (loss)	-162	-826
Prior service credit (cost)	'	2
Total accumulated other comprehensive income (loss)	-162	-824
Other Postretirement Benefits	'	'
Amounts recognized in the consolidated balance sheets consist of:	'	'
Current liability	-59	-71
Noncurrent liability	-1,703	-2,614
Total liability	-1,762	-2,685
Amounts recognized in accumulated other comprehensive income (loss) consist of:	'	'
Net actuarial gain (loss)	555	-79
Prior service credit (cost)	306	-24
Total accumulated other comprehensive income (loss)	$861	($103)

Accumulated_Benefit_Obligation

Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'
Projected benefit obligation	$3,820	$4,387
Accumulated benefit obligation	3,245	3,869
Fair value of plan assets	$2,176	$1,991

Components_of_Net_Periodic_Ben

Components of Net Periodic Benefit Cost (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$121	$99	$88
Interest cost	191	184	178
Expected return on plan assets	-163	-138	-140
Curtailment loss	2	'	'
Amortization of prior service credits	'	-1	-2
Settlement (gain) loss	-10	1	1
Amortization of unrecognized actuarial (gain) loss	48	21	-20
Net periodic benefit cost	189	166	105
Other Postretirement Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	52	50	47
Interest cost	110	124	127
Expected return on plan assets	-2	-2	-2
Curtailment loss	2	'	'
Amortization of prior service credits	-3	'	'
Amortization of unrecognized actuarial (gain) loss	3	-3	-2
Net periodic benefit cost	$162	$169	$170

Amortized_Accumulated_Other_Co

Amortized Accumulated Other Comprehensive Income Into Net Periodic Benefit Cost (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Pension Benefits	'
Defined Benefit Plan Disclosure [Line Items]	'
Actuarial (gain) loss to be reclassified from accumulated other comprehensive income into net periodic benefit cost	$9
Other Postretirement Benefits	'
Defined Benefit Plan Disclosure [Line Items]	'
Actuarial (gain) loss to be reclassified from accumulated other comprehensive income into net periodic benefit cost	($46)

Assumptions_Used_for_Benefit_P

Assumptions Used for Benefit Plans (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits	'	'
Assumptions used to determine benefit obligations	'	'
Discount rate	5.09%	4.19%
Rate of compensation increase	3.49%	2.49%
Assumptions used to determine net expense	'	'
Discount rate	4.48%	5.02%
Expected return on plan assets	7.56%	7.54%
Rate of compensation increase	2.48%	2.48%
Other Postretirement Benefits	'	'
Assumptions used to determine benefit obligations	'	'
Discount rate	4.94%	4.12%
Assumptions used to determine net expense	'	'
Discount rate	4.12%	4.92%
Expected return on plan assets	4.00%	4.00%
Health care cost trend rate assumed for next year	7.25%	6.75%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2020)	5.00%	5.00%

Allocation_of_Plan_Asset_Detai

Allocation of Plan Asset (Detail) (United Airlines, Inc.)	12 Months Ended
	Dec. 31, 2013
Equity Securities	'
Defined Benefit Plan Disclosure [Line Items]	'
Percent of Total, minimum	42.00%
Percent of Total, maximum	52.00%
Expected Long-Term Rate of Return	9.50%
Fixed-Income Securities	'
Defined Benefit Plan Disclosure [Line Items]	'
Percent of Total, minimum	26.00%
Percent of Total, maximum	34.00%
Expected Long-Term Rate of Return	5.50%
Alternatives	'
Defined Benefit Plan Disclosure [Line Items]	'
Percent of Total, minimum	15.00%
Percent of Total, maximum	21.00%
Expected Long-Term Rate of Return	7.50%
Other Investments	'
Defined Benefit Plan Disclosure [Line Items]	'
Percent of Total, minimum	3.00%
Percent of Total, maximum	7.00%
Expected Long-Term Rate of Return	4.50%

Effect_of_OnePercentagePoint_C

Effect of One-Percentage-Point Change in Assumed Health Care Trend Rate (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]	'
Effect on total service and interest cost,1% Decrease	$10
Effect on post retirement benefit obligation, 1% Decrease	203
Other Postretirement Benefits	'
Defined Benefit Plan Disclosure [Line Items]	'
Effect on total service and interest cost,1% Increase	21
Effect on post retirement benefit obligation, 1% Increase	213
Effect on total service and interest cost,1% Decrease	-17
Effect on post retirement benefit obligation, 1% Decrease	($186)

Pension_and_Other_Postretireme3

Pension and Other Postretirement Plan Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	$293	$256	$249
Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	2,397	2,157	1,868
Pension Benefits | Equity Securities	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	1,158	1,034	'
Pension Benefits | Fixed-Income Securities	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	702	611	'
Pension Benefits | Alternatives	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	405	394	'
Pension Benefits | Insurance Contract	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	26	36	'
Pension Benefits | Other Investments	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	106	82	'
Other Postretirement Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	57	58	58
Other Postretirement Benefits | Deposit Administration Fund	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	57	58	'
Level 1 | Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	389	383	'
Level 1 | Pension Benefits | Equity Securities	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	389	383	'
Level 2 | Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	1,772	1,576	'
Level 2 | Pension Benefits | Equity Securities	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	769	651	'
Level 2 | Pension Benefits | Fixed-Income Securities	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	698	609	'
Level 2 | Pension Benefits | Alternatives	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	199	234	'
Level 2 | Pension Benefits | Other Investments	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	106	82	'
Level 3 | Pension Benefits	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	236	198	'
Level 3 | Pension Benefits | Fixed-Income Securities	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	4	2	'
Level 3 | Pension Benefits | Alternatives	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	206	160	'
Level 3 | Pension Benefits | Insurance Contract	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	26	36	'
Level 3 | Other Postretirement Benefits | Deposit Administration Fund	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement plan assets	$57	$58	'

Defined_Benefit_Plan_Assets_Me

Defined Benefit Plan Assets Measured at Fair Value Using Unobservable Inputs (Level Three) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance at beginning of year	$256	$249
Actual return on plan assets, Sold during the year	15	'
Actual return on plan assets, Held at year end	7	-47
Purchases, sales, issuances and settlements (net)	15	54
Balance at end of year	$293	$256

Estimated_Future_Benefit_Payme

Estimated Future Benefit Payments (Detail) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Pension Benefits	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	$247
2015	259
2016	265
2017	271
2018	268
Years 2019 - 2023	1,435
Other Postretirement Benefits	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	122
2015	123
2016	126
2017	129
2018	132
Years 2019 - 2023	717
Other Postretirement-Subsidy Receipts	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	6
2015	7
2016	7
2017	8
2018	9
Years 2019 - 2023	$53

MultiEmployer_Plans_Detail

Multi-Employer Plans (Detail) (Multiemployer Plans, Pension, IAM National Pension Plan, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Multiemployer Plans [Line Items]	'		'	'
EIN/ Pension Plan Number	'51-6031295 - 002		'	'
Pension Protection Act Zone Status (2013 and 2012)	'Green	[1]	'	'
FIP/RP Status Pending/Implemented	'No		'	'
United's Contributions	'		$351	'
Surcharge Imposed	'No		'	'
United Airlines, Inc.	'		'	'
Multiemployer Plans [Line Items]	'		'	'
United's Contributions	$38		$36	$34
[1]	Plans in the green zone are at least 80 percent funded.

MultiEmployer_Plans_Parentheti

Multi-Employer Plans (Parenthetical) (Detail) (IAM National Pension Plan, Minimum, Multiemployer Plans, Pension)	Dec. 31, 2013
IAM National Pension Plan | Minimum | Multiemployer Plans, Pension	'
Multiemployer Plans [Line Items]	'
Green zone funded percentage	80.00%

Financial_Assets_and_Liabiliti

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Convertible Debt Derivative Asset | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Convertible debt derivative asset	$480	$268
Convertible Debt Option Liability | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Convertible debt option liability	-270	-128
Fair Value, Measurements, Recurring | Cash and Cash Equivalents	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	3,220	4,770
Fair Value, Measurements, Recurring | Cash and Cash Equivalents | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	3,214	4,765
Fair Value, Measurements, Recurring | Auction Rate Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	105	116
Fair Value, Measurements, Recurring | Auction Rate Securities | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	105	116
Fair Value, Measurements, Recurring | CDARS	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	301	367
Fair Value, Measurements, Recurring | CDARS | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	301	367
Fair Value, Measurements, Recurring | Asset-backed Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	694	715
Fair Value, Measurements, Recurring | Asset-backed Securities | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	694	715
Fair Value, Measurements, Recurring | Corporate Debt	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	685	537
Fair Value, Measurements, Recurring | Corporate Debt | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	685	537
Fair Value, Measurements, Recurring | U.S. Government And Agency Notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	38	12
Fair Value, Measurements, Recurring | U.S. Government And Agency Notes | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	38	12
Fair Value, Measurements, Recurring | Other Fixed Income Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	78	26
Fair Value, Measurements, Recurring | Other Fixed Income Securities | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	78	26
Fair Value, Measurements, Recurring | Fuel Derivatives, Net	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	104	46
Fair Value, Measurements, Recurring | Fuel Derivatives, Net | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	104	46
Fair Value, Measurements, Recurring | Foreign Currency Derivatives, Net	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	1	'
Fair Value, Measurements, Recurring | Foreign Currency Derivatives, Net | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	1	'
Fair Value, Measurements, Recurring | Restricted Cash	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Restricted cash	395	447
Fair Value, Measurements, Recurring | Restricted Cash | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Restricted cash	395	447
Fair Value, Measurements, Recurring | Convertible Debt Derivative Asset | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Convertible debt derivative asset	480	268
Fair Value, Measurements, Recurring | Convertible Debt Option Liability | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Convertible debt option liability	-270	-128
Fair Value, Measurements, Recurring | EETC	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
EETC	61	63
Fair Value, Measurements, Recurring | EETC | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
EETC	61	63
Fair Value, Measurements, Recurring | Level 1 | Cash and Cash Equivalents	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	3,220	4,770
Fair Value, Measurements, Recurring | Level 1 | Cash and Cash Equivalents | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	3,214	4,765
Fair Value, Measurements, Recurring | Level 1 | Restricted Cash	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Restricted cash	395	447
Fair Value, Measurements, Recurring | Level 1 | Restricted Cash | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Restricted cash	395	447
Fair Value, Measurements, Recurring | Level 2 | CDARS	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	301	367
Fair Value, Measurements, Recurring | Level 2 | CDARS | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	301	367
Fair Value, Measurements, Recurring | Level 2 | Asset-backed Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	694	715
Fair Value, Measurements, Recurring | Level 2 | Asset-backed Securities | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	694	715
Fair Value, Measurements, Recurring | Level 2 | Corporate Debt	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	685	537
Fair Value, Measurements, Recurring | Level 2 | Corporate Debt | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	685	537
Fair Value, Measurements, Recurring | Level 2 | U.S. Government And Agency Notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	38	12
Fair Value, Measurements, Recurring | Level 2 | U.S. Government And Agency Notes | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	38	12
Fair Value, Measurements, Recurring | Level 2 | Other Fixed Income Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	78	26
Fair Value, Measurements, Recurring | Level 2 | Other Fixed Income Securities | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	78	26
Fair Value, Measurements, Recurring | Level 2 | Fuel Derivatives, Net	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	104	46
Fair Value, Measurements, Recurring | Level 2 | Fuel Derivatives, Net | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	104	46
Fair Value, Measurements, Recurring | Level 2 | Foreign Currency Derivatives, Net	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	1	'
Fair Value, Measurements, Recurring | Level 2 | Foreign Currency Derivatives, Net | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivatives, net	1	'
Fair Value, Measurements, Recurring | Level 3 | Auction Rate Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	105	116
Fair Value, Measurements, Recurring | Level 3 | Auction Rate Securities | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Short-term investments	105	116
Fair Value, Measurements, Recurring | Level 3 | Convertible Debt Derivative Asset | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Convertible debt derivative asset	480	268
Fair Value, Measurements, Recurring | Level 3 | Convertible Debt Option Liability | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Convertible debt option liability	-270	-128
Fair Value, Measurements, Recurring | Level 3 | EETC	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
EETC	61	63
Fair Value, Measurements, Recurring | Level 3 | EETC | United Airlines, Inc.	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
EETC	$61	$63

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2013
Asset-backed Securities | Minimum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'1 year
Asset-backed Securities | Maximum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'41 years
Corporate Debt | Minimum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'1 year
Corporate Debt | Maximum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'22 years
Auction Rate Securities | Minimum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'19 years
Auction Rate Securities | Maximum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'33 years
CDARS | Maximum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'1 year
U.S. Government and Other Securities	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'5 years
U.S. Government and Other Securities | Minimum	'
Fair Value [Line Items]	'
Available-for-sale securities remaining maturities	'1 year
EETC | Maximum	'
Fair Value [Line Items]	'
Available-for-sale securities maturity, year	'2019
6% convertible junior subordinated debentures due 2030	'
Fair Value [Line Items]	'
Debt instrument convertible stated interest rate	6.00%
Debt instrument maturity year	'2030
4.5% Convertible Notes Due 2015	'
Fair Value [Line Items]	'
Debt instrument convertible stated interest rate	4.50%
Debt instrument maturity year	'2015

Activity_for_Level_Three_Finan

Activity for "Level Three" Financial Assets and Financial Liabilities (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Ual And United | Auction Rate Securities	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning Balance	$116	$113
Purchases, (sales), issuances and settlements (net)	-19	'
Realized	3	'
Unrealized	1	1
Reported in other comprehensive income (loss)	4	2
Ending Balance	105	116
Ual And United | EETC	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning Balance	63	60
Purchases, (sales), issuances and settlements (net)	-4	-5
Reported in other comprehensive income (loss)	2	8
Ending Balance	61	63
United Airlines, Inc. | Convertible Debt Derivative Asset	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning Balance	268	193
Unrealized	212	75
Ending Balance	480	268
United Airlines, Inc. | Convertible Debt Option Liability	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning Balance	-128	-95
Purchases, (sales), issuances and settlements (net)	'	'
Realized	'	'
Unrealized	-142	-33
Reported in other comprehensive income (loss)	'	'
Ending Balance	($270)	($128)

Carrying_Values_and_Estimated_

Carrying Values and Estimated Fair Values of Financial Instruments (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	$11,708	'
Carrying (Reported) Amount, Fair Value Disclosure	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	11,539	12,252
Estimate of Fair Value, Fair Value Disclosure	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	12,695	13,419
Estimate of Fair Value, Fair Value Disclosure | Level 2	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	8,829	8,045
Estimate of Fair Value, Fair Value Disclosure | Level 3	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	3,866	5,374
United Airlines, Inc.	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	11,604	'
United Airlines, Inc. | Carrying (Reported) Amount, Fair Value Disclosure	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	11,388	11,850
United Airlines, Inc. | Estimate of Fair Value, Fair Value Disclosure	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	12,249	12,460
United Airlines, Inc. | Estimate of Fair Value, Fair Value Disclosure | Level 2	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	8,383	7,086
United Airlines, Inc. | Estimate of Fair Value, Fair Value Disclosure | Level 3	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt	$3,866	$5,374

Quantitative_Information_about

Quantitative Information about Level 3 Fair Value Measurements (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Auction Rate Securities	'
Fair Value Measurements [Line Items]	'
Level 3 Financial Instruments, asset	$105
Valuation Technique	'Valuation Service / Broker Quotes
Unobservable Input	'Broker quotes	[1]
EETC	'
Fair Value Measurements [Line Items]	'
Level 3 Financial Instruments, asset	61
Valuation Technique	'Discounted Cash Flows
Unobservable Input	'Structure credit risk	[2]
EETC | Structure Credit Risk	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, weighted average percentage	4.00%
EETC | Structure Credit Risk | Minimum	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, percentage	4.00%
EETC | Structure Credit Risk | Maximum	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, percentage	5.00%
Convertible Debt Derivative Asset	'
Fair Value Measurements [Line Items]	'
Level 3 Financial Instruments, asset	480
Valuation Technique	'Binomial Lattice Model
Unobservable Input	'Expected volatility Own credit risk	[3],[4]
Convertible Debt Derivative Asset | Expected Volatility	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, weighted average volatility percentage	46.00%
Convertible Debt Derivative Asset | Expected Volatility | Minimum	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, expected volatility percentage	45.00%
Convertible Debt Derivative Asset | Expected Volatility | Maximum	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, expected volatility percentage	60.00%
Convertible Debt Derivative Asset | Own Credit Risk	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, credit risk percentage	5.00%
Convertible Debt Option Liability	'
Fair Value Measurements [Line Items]	'
Level 3 Financial Instruments, liability	($270)
Valuation Technique	'Binomial Lattice Model
Unobservable Input	'Expected volatility Own credit risk	[3],[4]
Convertible Debt Option Liability | Expected Volatility	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, weighted average volatility percentage	47.00%
Convertible Debt Option Liability | Expected Volatility | Minimum	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, expected volatility percentage	45.00%
Convertible Debt Option Liability | Expected Volatility | Maximum	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, expected volatility percentage	60.00%
Convertible Debt Option Liability | Own Credit Risk	'
Fair Value Measurements [Line Items]	'
Level 3 fair value measurements, credit risk percentage	5.00%
[1]	Broker quotes obtained by a third-party valuation service.
[2]	Represents the credit risk premium of the EETC structure above the risk-free rate that the Company has determined market participants would use in pricing the instruments.
[3]	Represents the range in volatility estimates that the Company has determined market participants would use when pricing the instruments.
[4]	Represents the range of Company-specific risk adjustments that the Company has determined market participants would use as a model input.

Hedging_Activities_Additional_

Hedging Activities - Additional Information (Detail)	Dec. 31, 2013
	gal
2014 Projected	'
Derivatives And Hedging Activities [Line Items]	'
Percentage of projected fuel requirements	24.00%
Volume of fuel hedging	951,000,000
2015 Projected	'
Derivatives And Hedging Activities [Line Items]	'
Percentage of projected fuel requirements	8.00%
Volume of fuel hedging	309,000,000

Description_of_Derivative_Inst

Description of Derivative Instruments (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	$104	$51
Fuel contracts, liabilities	'	5
Receivables	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	89	51
Other Assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	15	'
Current liabilities: Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, liabilities	'	4
Other liabilities and deferred credits: Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, liabilities	'	1
Hedge Derivatives, Net | Cash Flow Hedging	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	25	7
Hedge Derivatives, Net | Cash Flow Hedging | Receivables	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	19	7
Hedge Derivatives, Net | Cash Flow Hedging | Other Assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	6	'
Hedge Derivatives, Net | Cash Flow Hedging | Current liabilities: Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, liabilities	'	2
Not Designated as Hedging Instrument	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	79	44
Fuel contracts, liabilities	'	3
Not Designated as Hedging Instrument | Receivables	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	70	44
Not Designated as Hedging Instrument | Other Assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, assets	9	'
Not Designated as Hedging Instrument | Current liabilities: Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, liabilities	'	2
Not Designated as Hedging Instrument | Other liabilities and deferred credits: Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fuel contracts, liabilities	'	$1

Offsetting_Assets_and_Liabilit

Offsetting Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Offsetting Asset and Liabilities [Line Items]	'	'
Potential net fair value positions elected to offset	$104	$46
Receivables	'	'
Offsetting Asset and Liabilities [Line Items]	'	'
Potential net fair value positions elected to offset	89	46
Other Assets	'	'
Offsetting Asset and Liabilities [Line Items]	'	'
Potential net fair value positions elected to offset	$15	'

Schedule_of_Gains_Losses_on_De

Schedule of Gains (Losses) on Derivative Instruments (Detail) (Hedge Derivatives, Net, Cash Flow Hedging, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Hedge Derivatives, Net | Cash Flow Hedging	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	$39	($51)
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	18	-141
Amount of Gain (Loss) Recognized in Nonoperating Expense (Ineffective Portion)	$5	($1)

Schedule_of_Derivative_Instrum

Schedule of Derivative Instruments not Designated as Hedges Gains (Losses) (Detail) (Not Designated as Hedging Instrument, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Not Designated as Hedging Instrument	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Amount of Gain Recognized in Nonoperating income (expense): Miscellaneous, net	$79	$38

Schedule_of_Derivative_Credit_

Schedule of Derivative Credit Risk and Fair Value (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivative [Line Items]	'	'
Net derivative assets with counterparties	$104	$46
Collateral held by the Company (classified as an other current liability)	'	'
Potential loss related to the failure of the Company's counterparties to perform	$104	$46

Debt_Detail

Debt (Detail) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Aug. 31, 2010
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'		'		'
Less: current portion of long-term debt-United	($1,368)		($1,812)		'
Long-term debt, net	10,171		10,440		'
United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	11,604		12,059		'
Less: unamortized debt discount	-169		-152		'
Less: current portion of long-term debt-United	-1,368		-1,812		'
Long-term debt, net	10,020		10,038		'
6% convertible senior notes due 2029	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	104		345		'
Secured Debt | Notes payable, fixed interest rates of 4.00% to 12.00% (weighted average rate of 6.50% as of December 31, 2013), payable through 2025 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	6,279		5,943		'
Secured Debt | Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	1,243		1,668		'
Secured Debt | Term Loan | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	893		'		'
Secured Debt | Amended credit facility, LIBOR plus 2.0%, due 2014 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	'		1,201		'
Secured Debt | 6.75% senior secured notes due 2015 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	800		800		800
Secured Debt | 9.875% senior secured notes and 12% second lien due 2013 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	'		600		'
Unsecured Debt | UAL 4.5% Senior Limited-Subordination Convertible Notes Due 2021 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	156		156		'
Unsecured Debt | United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	652		652		'
Unsecured Debt | Senior Notes 6% Due 2020 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	300		'		'
Unsecured Debt | 6% convertible junior subordinated debentures due 2030 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	248		248		'
Unsecured Debt | Senior Notes 6.375 Percent Due 2018 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	300		'		'
Unsecured Debt | 8% notes due 2024 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	400		400		'
Unsecured Debt | 4.5% convertible notes due 2015 | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	230		230		'
Unsecured Debt | Other Debt | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term Debt, Gross	103		161		'
Adjusted For Embedded Conversion Options | United Airlines, Inc.	'		'		'
Debt Instrument [Line Items]	'		'		'
Long-term debt, net	$10,067	[1]	$10,095	[1]	'
[1]	As further described below under "Convertible Debt Securities and Derivatives," there is a basis difference between UAL and United debt values, because we were required to apply different accounting methodologies. The United debt presented above does not agree to United's balance sheet by the amount of this adjustment.

Debt_Parenthetical_Detail

Debt (Parenthetical) (Detail)

Jun. 30, 2013

Nov. 30, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

31-May-13

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Interest Rate Floor

Unsecured Debt

6.75% senior secured notes due 2015

Senior Notes 6% Due 2020

6% convertible junior subordinated debentures due 2030

Senior Notes 6.375 Percent Due 2018

Senior Notes 6.375 Percent Due 2018

6% convertible senior notes due 2029

6% convertible senior notes due 2029

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

Unsecured Debt

Unsecured Debt

Notes payable, fixed interest rates of 4.00% to 12.00% (weighted average rate of 6.50% as of December 31, 2013), payable through 2025

Notes payable, fixed interest rates of 4.00% to 12.00% (weighted average rate of 6.50% as of December 31, 2013), payable through 2025

Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025

Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025

Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025

Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025

Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025

Notes payable, floating interest rates of the London Interbank Offered Rate ("LIBOR") plus 0.20% to 5.46%, payable through 2025

Term Loan

Term Loan

Term Loan

Term Loan

Amended credit facility, LIBOR plus 2.0%, due 2014

Amended credit facility, LIBOR plus 2.0%, due 2014

6.75% senior secured notes due 2015

6.75% senior secured notes due 2015

6.75% senior secured notes due 2015

9.875% Senior Notes Due 2013

9.875% Senior Notes Due 2013

12% Second Lien Due 2013

12% Second Lien Due 2013

UAL 4.5% Senior Limited-Subordination Convertible Notes Due 2021

UAL 4.5% Senior Limited-Subordination Convertible Notes Due 2021

United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight

United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight

United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight

United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight

United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight

United Air Lines Six Percent Senior Notes Due Twenty Twenty Six to Twenty Twenty Eight

Senior Notes 6% Due 2020

Senior Notes 6% Due 2020

6% convertible junior subordinated debentures due 2030

6% convertible junior subordinated debentures due 2030

Senior Notes 6.375 Percent Due 2018

Senior Notes 6.375 Percent Due 2018

8% notes due 2024

8% notes due 2024

4.5% convertible notes due 2015

4.5% convertible notes due 2015

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Minimum

Minimum

Maximum

Maximum

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Minimum

Minimum

Maximum

Maximum

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Secured Debt

Secured Debt

Secured Debt

Secured Debt

Interest Rate Floor

Libor Plus

Certain Market Interest Rates

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument stated interest rate, minimum

'

'

'

'

'

'

'

'

'

'

4.00%

4.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument stated interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.20%

0.20%

5.46%

5.46%

'

1.00%

3.00%

2.00%

2.00%

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument stated interest rate

1.00%

6.00%

6.75%

6.00%

6.00%

6.38%

6.38%

6.00%

6.00%

4.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.75%

6.75%

6.75%

9.88%

9.88%

12.00%

12.00%

4.50%

4.50%

6.00%

6.00%

'

'

'

'

6.00%

6.00%

6.00%

6.00%

6.38%

6.38%

8.00%

8.00%

4.50%

4.50%

Debt instrument stated interest rate, maximum

'

'

'

'

'

'

'

'

'

'

12.00%

12.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average interest rate

'

'

'

'

'

'

'

'

'

'

6.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, maturity date

'

'

'

'

'2030

'

'

'2029

'2029

'

'2025

'2025

'2025

'2025

'

'

'

'

'2019

'

'

'

'2014

'2014

'2015

'2015

'2015

'2013

'2013

'

'

'2021

'2021

'

'

'2026

'2026

'2028

'2028

'2020

'2020

'2030

'2030

'2018

'2018

'2024

'2024

'2015

'2015

Contractual_Principal_Payments

Contractual Principal Payments (Detail) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'
2014	$1,368
2015	2,072
2016	1,051
2017	614
2018	1,135
After 2018	5,468
Long term debt	11,708
United Airlines, Inc.	'
Debt Instrument [Line Items]	'
2014	1,368
2015	2,072
2016	1,051
2017	614
2018	1,135
After 2018	5,364
Long term debt	$11,604

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)

6 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

6 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

2 Months Ended

12 Months Ended

Jun. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Mar. 27, 2013

Mar. 27, 2013

Dec. 31, 2013

Mar. 27, 2013

Dec. 31, 2013

Jun. 30, 2013

Nov. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Dec. 31, 2013

31-May-13

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Feb. 20, 2014

Jan. 17, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2011

Dec. 31, 2013

Dec. 31, 2012

Feb. 20, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Term Loan Facility

Amended Credit Facility

Performance Bonds

Revolving Credit Facility

Revolving Credit Facility

Interest Rate Floor

Unsecured Debt

LIBOR

Certain Market Interest Rates

Senior Notes 6.375 Percent Due 2018

Senior Notes 6.375 Percent Due 2018

6% convertible senior notes due 2029

6% convertible senior notes due 2029

6% convertible senior notes due 2029

6% convertible senior notes due 2029

6% convertible senior notes due 2029

6% convertible senior notes due 2029

6.75% senior secured notes due 2015

6% Convertible Senior Notes

6% Convertible Senior Notes

8% notes due 2024

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

Unsecured Debt

Debtor Optional Redemption Period

Holder Optional Redemption Period 1

Holder Optional Redemption Period 2

Holder Optional Redemption Period 3

Subsequent Event

Subsequent Event

Letter of Credit

Letter of Credit and Performance Bonds

Convertible Debt Derivative Asset

Convertible Debt Derivative Asset

Convertible Debt Option Liability

Convertible Debt Option Liability

Unsecured Debt

Adjusted For Embedded Conversion Options

Adjusted For Embedded Conversion Options

Subsequent Event

Senior Notes 6.375 Percent Due 2018

Senior Notes 6.375 Percent Due 2018

6% convertible junior subordinated debentures due 2030

6% convertible junior subordinated debentures due 2030

6% convertible junior subordinated debentures due 2030

6.75% senior secured notes due 2015

6.75% senior secured notes due 2015

6.75% senior secured notes due 2015

8% notes due 2024

8% notes due 2024

Pass Through Certificates

4.5% convertible notes due 2015

United Five Percentage Convertible Notes

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Secured Debt

Secured Debt

Secured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Unsecured Debt

Convertible Common Stock

Convertible Preferred Stock

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount

'

'

'

'

$1,200,000,000

'

'

'

'

$300,000,000

'

'

'

$300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$726,000,000

'

'

'

'

'

$248,000,000

'

'

'

'

'

'

'

'

'

'

Debt instrument maturity date

'

'

'

1-Apr-19

'

'

1-Apr-18

'

'

1-Dec-20

'

'

'

1-Jun-18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15-Nov-30

'

'

'

'

'

'

'

'

'

'

Debt instrument stated interest rate

'

'

'

'

'

'

'

'

1.00%

6.00%

'

'

6.38%

6.38%

6.00%

6.00%

'

'

'

'

6.75%

'

'

'

'

'

'

'

'

'

'

'

4.50%

'

'

4.50%

6.38%

6.38%

'

'

'

6.75%

6.75%

6.75%

8.00%

8.00%

'

'

'

Debt instrument redemption percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

101.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument convertible effective interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

'

'

'

'

'

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

'

'

'

'

'

'

'

'

4.50%

5.00%

Debt instrument maturity year

'

'

'

'

'2014

'

'

'

'

'

'

'

'

'

'2029

'2029

'

'

'

'

'

'2029

'

'

'

'

'

'

'

'

'

'

'

'

'

'2021

'2018

'2018

'

'

'

'2015

'2015

'2015

'2024

'2024

'

'

'2023

Conversion price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$8.69

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$32.64

'

'

'

'

'

'

$57.14

$0.88

'

'

'

'

'

'

$18.93

'

Convertible senior notes redemption date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15-Oct-14

15-Oct-14

15-Oct-19

15-Oct-24

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued in exchange for convertible notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,000,000

3,582,640

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount of convertible senior notes exchanged

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

240,000,000

31,126,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Gross

'

'

'

'

'

'

'

'

'

'

'

'

'

'

104,000,000

345,000,000

'

'

'

'

'

104,000,000

'

'

11,604,000,000

12,059,000,000

'

'

'

'

'

'

'

'

'

'

300,000,000

'

'

'

'

800,000,000

800,000,000

800,000,000

400,000,000

400,000,000

'

'

'

Repurchased debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

570,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument converted amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

156,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument conversion rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30.6419

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument converted shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount of debt redeemed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit Agreement

'

'

'

900,000,000

'

'

1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Available under revolving credit facility

'

'

'

'

'

'

'

1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

3.00%

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Quarterly principal repayment amount

0.25%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commencement date of installment payment

30-Jun-13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, maturity date

1-Apr-19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commitment fee percentage

0.75%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount utilized to repay term loan

'

'

'

900,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash utilized to repay term loan

'

'

'

'

300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility outstanding amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

61,000,000

398,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility expiration year

'

'

'

'

'

'2018

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long term debt

'

11,708,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,604,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,000,000,000

'

'

Convertible preferred securities, outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

'

'

'

'

'

'

'

'

Liquidation value per preferred security

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$50

'

'

'

'

'

'

'

'

'

'

Preferred securities liquidation value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

248,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt, net

'

10,171,000,000

10,440,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,020,000,000

10,038,000,000

'

'

'

'

'

'

'

10,067,000,000

[1]

10,095,000,000

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Difference in long term debt noncurrent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

47,000,000

57,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debt derivative asset

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

480,000,000

268,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debt option liability

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$270,000,000

$128,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

As further described below under "Convertible Debt Securities and Derivatives," there is a basis difference between UAL and United debt values, because we were required to apply different accounting methodologies. The United debt presented above does not agree to United's balance sheet by the amount of this adjustment.

Details_of_Pass_Through_Trusts

Details of Pass Through Trusts (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]	'	'	'
Proceeds received from issuance of debt	$1,423	$1,121	$152
United Airlines, Inc.	'	'	'
Debt Instrument [Line Items]	'	'	'
Total debt recorded	11,604	12,059	'
Proceeds received from issuance of debt	1,423	1,121	152
United Airlines, Inc. | Class A Pass Through Certificates | August 2013	'	'	'
Debt Instrument [Line Items]	'	'	'
Principal	720	'	'
Final expected distribution date	'2025-08	'	'
Stated interest rate	4.30%	'	'
Total debt recorded	153	'	'
Proceeds received from issuance of debt	153	'	'
Remaining proceeds from issuance of debt to be received in future periods	567	'	'
United Airlines, Inc. | Class A Pass Through Certificates | October 2012	'	'	'
Debt Instrument [Line Items]	'	'	'
Principal	712	'	'
Final expected distribution date	'2024-10	'	'
Stated interest rate	4.00%	'	'
Total debt recorded	712	'	'
Proceeds received from issuance of debt	465	'	'
United Airlines, Inc. | Class B Pass Through Certificates | August 2013	'	'	'
Debt Instrument [Line Items]	'	'	'
Principal	209	'	'
Final expected distribution date	'2021-08	'	'
Stated interest rate	5.38%	'	'
Total debt recorded	44	'	'
Proceeds received from issuance of debt	44	'	'
Remaining proceeds from issuance of debt to be received in future periods	165	'	'
United Airlines, Inc. | Class B Pass Through Certificates | October 2012	'	'	'
Debt Instrument [Line Items]	'	'	'
Principal	132	'	'
Final expected distribution date	'2020-10	'	'
Stated interest rate	5.50%	'	'
Total debt recorded	132	'	'
Proceeds received from issuance of debt	86	'	'
United Airlines, Inc. | Class C Pass Through Certificates | December 2012	'	'	'
Debt Instrument [Line Items]	'	'	'
Principal	425	'	'
Final expected distribution date	'2018-04	'	'
Stated interest rate	6.13%	'	'
Total debt recorded	425	'	'
Proceeds received from issuance of debt	147	'	'
United Airlines, Inc. | EETC	'	'	'
Debt Instrument [Line Items]	'	'	'
Principal	2,198	'	'
Total debt recorded	1,466	'	'
Proceeds received from issuance of debt	895	'	'
Remaining proceeds from issuance of debt to be received in future periods	$732	'	'

Summary_of_Collateral_Covenant

Summary of Collateral Covenants and Cross Default Provisions (Detail)	12 Months Ended
	Dec. 31, 2013
Credit Agreement	'
Debt Instrument [Line Items]	'
Collateral, Covenants and Cross Default Provisions	'Secured by certain of United's international route authorities, specified take-off and landing slots at certain airports and certain other assets. The Credit Agreement requires the Company to maintain at least $3.0 billion of unrestricted liquidity at all times, which includes unrestricted cash, short-term investments and any undrawn amounts under any revolving credit facility and to maintain a minimum ratio of appraised value of collateral to the outstanding obligations under the Credit Agreement of 1.67 to 1.0 at all times. The Credit Agreement contains covenants that, among other things, restrict the ability of UAL and its restricted subsidiaries (as defined in the Credit Agreement) to incur additional indebtedness and to pay dividends on or repurchase stock. The Credit Agreement contains events of default customary for this type of financing, including a cross default and cross acceleration provision to certain other material indebtedness of the Company.
United Air Lines 6% Notes Due 2026	'
Debt Instrument [Line Items]	'
Collateral, Covenants and Cross Default Provisions	'The amended and restated indenture for these notes, which are unsecured, contains covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indenture) to incur additional indebtedness and pay dividends on or repurchase stock.
United Air Lines 6% Notes Due 2028	'
Debt Instrument [Line Items]	'
Collateral, Covenants and Cross Default Provisions	'These covenants cease to be in effect when the indenture covering the 6.375% Senior Notes due 2018 is discharged. The indenture contains events of default that are customary for similar financings.
Senior Notes 6.375 Percent Due 2018	'
Debt Instrument [Line Items]	'
Collateral, Covenants and Cross Default Provisions	'The indentures for these notes, which are unsecured, contain covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indenture) to incur additional indebtedness and pay dividends on or repurchase stock.
Senior Notes 6% Due 2020	'
Debt Instrument [Line Items]	'
Collateral, Covenants and Cross Default Provisions	'The indentures contain events of default that are customary for similar financings.
6.75% senior secured notes due 2015	'
Debt Instrument [Line Items]	'
Collateral, Covenants and Cross Default Provisions	'Secured by certain of United's U.S.-Asia and U.S.-London Heathrow routes and related assets, all of the outstanding common stock and other assets of Air Micronesia, Inc. ("AMI") and Continental Micronesia, Inc. ("CMI") and substantially all of the other assets of AMI and CMI, including route authorities and related assets. The indenture for these notes includes covenants that, among other things, restrict United's ability to sell assets, incur additional indebtedness, issue preferred stock, make investments and pay dividends on or repurchase stock. In addition, if United fails to maintain a collateral coverage ratio of 1.5 to 1.0, United must pay additional interest on the Senior Notes at the rate of 2% per annum until the collateral coverage ratio equals at least 1.5 to 1.0. The indenture for these notes also includes events of default customary for similar financings and a cross default provision if United fails to make payment when due with respect to certain obligations regarding frequent flyer miles purchased by Chase under United's Co-Brand Agreement.

Summary_of_Collateral_Covenant1

Summary of Collateral Covenants and Cross Default Provisions (Parenthetical) (Detail) (USD $)	12 Months Ended
In Billions, unless otherwise specified	Dec. 31, 2013
Credit Agreement	'
Debt Instrument [Line Items]	'
Unrestricted liquidity required for credit agreement	3
Minimum ratio of appraised value of collateral for Credit Agreement	1.67
United Air Lines 6% Notes Due 2026	'
Debt Instrument [Line Items]	'
Debt instrument stated interest rate	6.00%
Debt instrument maturity year	'2026
United Air Lines 6% Notes Due 2028	'
Debt Instrument [Line Items]	'
Debt instrument stated interest rate	6.00%
Debt instrument maturity year	'2028
Senior Notes 6.375 Percent Due 2018	'
Debt Instrument [Line Items]	'
Debt instrument stated interest rate	6.38%
Debt instrument maturity year	'2018
Senior Notes 6% Due 2020	'
Debt Instrument [Line Items]	'
Debt instrument stated interest rate	6.00%
Debt instrument maturity year	'2020
6.75% senior secured notes due 2015	'
Debt Instrument [Line Items]	'
Debt instrument stated interest rate	6.75%
Debt instrument maturity year	'2015
Debt covenant required collateral coverage ratio	1.5
Additional interest paid if non-compliant on collateral coverage ratio	2.00%

Advanced_Purchase_of_Miles_Add

Advanced Purchase of Miles - Additional Information (Detail) (United Airlines, Inc., Co-Brand Agreement, USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
6.75% senior secured notes due 2015	'
Airline Products and Services [Line Items]	'
Debt instrument maturity year	'2015
Maximum	'
Airline Products and Services [Line Items]	'
Secured obligations	850
Maximum | Advanced Purchase of Miles	'
Airline Products and Services [Line Items]	'
Repurchase of pre-purchased miles from Chase in 2014	199
Repurchase of pre-purchased miles from Chase in 2015	224
Repurchase of pre-purchased miles from Chase in 2016	249

Future_Minimum_Lease_Payments_

Future Minimum Lease Payments for Capital and Operating Leases (Detail) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Capital Leases	'		'
2014	$206	[1]	'
2015	183	[1]	'
2016	168	[1]	'
2017	123	[1]	'
2018	106	[1]	'
After 2018	678	[1]	'
Minimum lease payments	1,464	[1]	'
Imputed interest	-594	[1]	'
Present value of minimum lease payments	870	[1]	'
Current portion	-117	[1]	-122
Long-term obligations under capital leases	753	[1]	792
Facility And Other Operating Leases	'		'
Operating Leases	'		'
2014	1,192		'
2015	987		'
2016	864		'
2017	831		'
2018	710		'
After 2018	6,002		'
Minimum lease payments	10,586		'
Aircraft Operating Leases	'		'
Operating Leases	'		'
2014	1,601	[2]	'
2015	1,381	[2]	'
2016	1,150	[2]	'
2017	1,053	[2]	'
2018	786	[2]	'
After 2018	1,819	[2]	'
Minimum lease payments	$7,790	[2]	'
[1]	As of December 31, 2013, United's aircraft capital lease minimum payments relate to leases of 47 mainline and 38 regional aircraft as well as to leases of nonaircraft assets. Imputed interest rate ranges are 4.8% to 18.5%.
[2]	The operating lease payments presented above include future payments of $103 million related to 25 nonoperating aircraft as of December 31, 2013.

Future_Minimum_Lease_Payments_1

Future Minimum Lease Payments for Capital and Operating Leases (Parenthetical) (Detail) (United Airlines, Inc., USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Minimum	'
Capital Leases And Operating Leases [Line Items]	'
Imputed interest rate	4.80%
Maximum	'
Capital Leases And Operating Leases [Line Items]	'
Imputed interest rate	18.50%
Mainline	'
Capital Leases And Operating Leases [Line Items]	'
Number of assets subject to lease	47
Regional Carrier	'
Capital Leases And Operating Leases [Line Items]	'
Number of assets subject to lease	38
Nonoperating Aircraft	'
Capital Leases And Operating Leases [Line Items]	'
Number of assets subject to lease	25
Operating lease future payments	103

Leases_and_Capacity_Purchase_A2

Leases and Capacity Purchase Agreements - Additional Information (Detail) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Apr. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Apr. 30, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

31-May-13

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Nov. 30, 2013

Aircraft

Minimum

Maximum

10% increase or decrease in scheduled block hours

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

United Airlines, Inc.

Sky West Incorporation

Aircraft Operating Leases

Aircraft Operating Leases

Aircraft Operating Leases

Lease Amendment

Capacity Purchase Agreements

Variable Interest Entity, Not Primary Beneficiary

Capacity Purchase Agreements

Capacity Purchase Agreements

Regional Aircraft

Regional Aircraft

Regional Aircraft

Revaluation of Liabilities

Revaluation of Liabilities

Revaluation of Liabilities

Minimum

Maximum

Capacity Purchase Agreements

Minimum

Maximum

United Airlines, Inc.

Aircraft

Aircraft

Aircraft

Seat

Operating Leased Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating lease term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 years

'26 years

'4 years

Operating lease expiration date, in years

'

'

'

'

'

'

'2033

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2014

'2024

'

Operating lease extended expiration year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2041

'

'

'

Operating leases obligations

'

'

'

'

'

'

'

'

'

'

$1,600,000,000

'

'

'

'

'

'

'

'

'

'

'

$7,790,000,000

[1]

'

'

'

Additional investment commitments

'

'

'

'

'

'

150,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

450,000,000

Nonaircraft rent expense

'

'

'

'

'

'

'

1,300,000,000

1,300,000,000

1,300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Regional capacity purchase expense

2,419,000,000

2,470,000,000

2,403,000,000

'

'

'

'

2,419,000,000

2,470,000,000

2,403,000,000

'

'

'

428,000,000

463,000,000

498,000,000

'

'

'

'

'

'

'

'

'

'

Lease Fair Value Adjustment, Remaining Lease Term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'11 years

'

'

'

'

'

Net accretion amounts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

173,000,000

240,000,000

227,000,000

'

'

'

'

'

'

'

Number of regional aircraft

'

133

'

'

'

'

'

'

'

'

'

30

572

'

'

'

'

'

'

'

'

40

'

'

'

'

Airline capacity purchase arrangements, expiration year

'

'

'

'

'

'

'

'

'

'

'

'

'2027

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of seats in the aircraft

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

76

'

'

'

'

Number of aircraft purchase

'

'

'

'

'

'

'

'

'

'

'

30

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Projected inflation rate

'

'

'

1.38%

2.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Scheduled block hours increase (decrease) percentage

'

'

'

'

'

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in cash obligation

'

'

'

'

'

$159,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash obligation increase (decrease) percentage

'

'

'

'

'

8.20%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The operating lease payments presented above include future payments of $103 million related to 25 nonoperating aircraft as of December 31, 2013.

Future_Lease_Payment_Under_Ter

Future Lease Payment Under Terms of Capacity Purchase Agreement (Detail) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Long-term Purchase Commitment [Line Items]	'
2014	$1,936
2015	1,747
2016	1,532
2017	1,449
2018	1,340
After 2018	3,410
Contractual Obligation, Total	$11,414

Variable_Interest_Entities_Add

Variable Interest Entities - Additional Information (Detail) (Variable Interest Entity, Not Primary Beneficiary)	Dec. 31, 2013
	Aircraft
Mainline	'
Variable Interest Entity [Line Items]	'
Aircraft under operating lease, fixed purchase options	72
Regional Carrier	'
Variable Interest Entity [Line Items]	'
Aircraft under operating lease	256

Firm_Commitments_to_Purchase_A

Firm Commitments to Purchase Aircraft (Detail) (United Airlines, Inc., Capital Addition Purchase Commitments)	Dec. 31, 2013
	Aircraft
Airbus A350-1000 aircraft	'
Commitments [Line Items]	'
Number of new aircraft committed to purchase	35	[1]
Boeing 737-900ER aircraft	'
Commitments [Line Items]	'
Number of new aircraft committed to purchase	63	[1]
Boeing 737 MAX 9 Aircraft	'
Commitments [Line Items]	'
Number of new aircraft committed to purchase	100	[1]
Boeing 787-8/-9/-10	'
Commitments [Line Items]	'
Number of new aircraft committed to purchase	57	[1]
Embraer EMB175 aircraft	'
Commitments [Line Items]	'
Number of new aircraft committed to purchase	30	[1]
[1]	United also has options and purchase rights for additional aircraft.

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)

12 Months Ended

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Tax-exempt special facilities revenue bonds

Tax-exempt special facilities revenue bonds

United Airlines, Inc.

United Airlines, Inc.

Floating Rate Debt

Fixed Rate Debt

Loans And Leases From Non U S Entities

Capital Addition Purchase Commitments

Capital Addition Purchase Commitments

Capital Addition Purchase Commitments

Maximum

Maximum

Maximum

Maximum

Minimum

Minimum

Minimum

Indirect Guarantee of Indebtedness

Employee

Boeing 737-900ER aircraft

Boeing 787-8 aircraft

Y

Tax-exempt special facilities revenue bonds

Tax-exempt special facilities revenue bonds

Loans And Leases From Non U S Entities

Tax-exempt special facilities revenue bonds

Tax-exempt special facilities revenue bonds

Aircraft

Aircraft

Indirect Guarantee of Indebtedness

Y

Indirect Guarantee of Indebtedness

Commitments and Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

New aircraft, scheduled delivery date

'

'

'

'

'

'

'

'

'

'

'

'2025

'

'

'

'2014

'

'

New aircraft, scheduled delivery date

'

'

'

'

'

'

'

'

'2014-06

'

'

'

'

'

'

'

'

'

Number of aircraft expected to be delivered

'

'

'

'

'

'

'

'

'

15

2

'

'

'

'

'

'

'

Guarantor obligations, maximum exposure

'

$1,900,000,000

$250,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating leases obligations

'

1,600,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital leases obligations

'

267,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, maturity year

'

'

'

'

'

'

'

'

'

'

'

'

'2038

'2041

'

'

'2015

'2014

Debt instrument principal amount

'

'

'

11,604,000,000

12,059,000,000

2,100,000,000

286,000,000

2,300,000,000

'

'

'

'

'

'

'

'

'

'

Debt instrument, remaining terms (years)

'

'

'

'

'

'

'

'

'

'

'

12

'

'

12

'

'

'

Contingent liabilities based on participation

'

'

$1,200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of employees

'

'

'

87,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of employees represented by various U.S. labor organizations

80.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Schedule_of_Acquisition_of_Air

Schedule of Acquisition of Aircrafts and Related Spare Engines (Detail) (USD $)	Dec. 31, 2013
In Billions, unless otherwise specified
Unrecorded Unconditional Purchase Obligation [Line Items]	'
2014	$3
2015	2.8
2016	2
2017	1.5
2018	2.1
After 2018	12.5
Total commitments	$23.90

Supplemental_Disclosures_of_Ca

Supplemental Disclosures of Cash Flow Information and Non-Cash Investing and Financing Activities (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash paid (refunded) during the period for:	'	'	'
Interest (net of amounts capitalized)	$752,000,000	$766,000,000	$855,000,000
Income taxes	-20,000,000	2,000,000	10,000,000
Non-cash transactions:	'	'	'
Net property and equipment acquired through issuance of debt	229,000,000	544,000,000	130,000,000
8% Contingent Senior Unsecured Notes and 6% Senior Notes, net of discount	'	357,000,000	88,000,000
Special facility payment financing	'	101,000,000	'
Interest paid in kind on 6% Senior Notes	'	'	37,000,000
Airport construction financing	40,000,000	50,000,000	'
UAL 6% Senior Convertible Notes	'	'	'
Non-cash transactions:	'	'	'
Exchanges of certain 6% convertible senior notes for common stock	240,000,000	'	'
United Airlines, Inc.	'	'	'
Cash paid (refunded) during the period for:	'	'	'
Interest (net of amounts capitalized)	752,000,000	766,000,000	855,000,000
Income taxes	-15,000,000	4,000,000	2,000,000
Non-cash transactions:	'	'	'
Net property and equipment acquired through issuance of debt	229,000,000	544,000,000	130,000,000
8% Contingent Senior Unsecured Notes and 6% Senior Notes, net of discount	'	357,000,000	88,000,000
Special facility payment financing	'	101,000,000	'
Interest paid in kind on 6% Senior Notes	'	'	37,000,000
Airport construction financing	$40,000,000	$50,000,000	'

Supplemental_Disclosures_of_Ca1

Supplemental Disclosures of Cash Flow Information and Non-Cash Investing and Financing Activities (Parenthetical) (Detail)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
UAL 6% Senior Convertible Notes	'	'	'
Supplemental Cash Flow Information [Line Items]	'	'	'
Debt instrument stated interest rate	6.00%	6.00%	6.00%
UAL 8% Contingent Senior Notes	'	'	'
Supplemental Cash Flow Information [Line Items]	'	'	'
Debt instrument stated interest rate	'	8.00%	8.00%
United Airlines, Inc. | UAL 6% Senior Convertible Notes	'	'	'
Supplemental Cash Flow Information [Line Items]	'	'	'
Debt instrument stated interest rate	6.00%	6.00%	6.00%
United Airlines, Inc. | UAL 8% Contingent Senior Notes	'	'	'
Supplemental Cash Flow Information [Line Items]	'	'	'
Debt instrument stated interest rate	'	8.00%	8.00%

Components_of_Special_Charges_

Components of Special Charges (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Special Charges [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Integration-related costs	$40	$50	$45	$70	$408	$60	$137	$134	$205	$739	$517
Labor agreement costs	'	127	'	'	21	454	'	'	127	475	'
Severance and benefits	91	'	'	14	'	'	76	49	105	125	'
Asset impairments	33	'	'	'	24	'	'	6	33	30	4
Termination of maintenance service contract	'	'	'	'	'	'	'	'	-5	'	58
Additional costs associated with the temporarily grounded Boeing 787 aircraft	'	'	7	11	'	'	'	'	18	'	'
(Gains) losses on sale of assets and other special charges, net	1	34	'	-3	-14	'	-7	-25	32	-46	13
Total	'	'	'	'	'	'	'	'	$520	$1,323	$592

IntegrationRelated_Costs_and_S2

Integration-Related Costs and Special Items - Additional Information (Detail) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Mar. 31, 2013

Jun. 30, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Oct. 31, 2013

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Mar. 31, 2012

Dec. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Aircraft

Employee

Attendant

Employee

Aircraft

International Association Of Machinists

8% Notes Indenture

UAL 8% Contingent Senior Notes

UAL 8% Contingent Senior Notes

United Air Lines 8% Senior Notes Due 2024

UAL 6% Senior Convertible Notes

UAL 6% Senior Convertible Notes

UAL 6% Senior Convertible Notes

United Air Lines 6% Notes Due 2026

United Air Lines 6% Notes Due 2026

United Air Lines 6% Notes Due 2028

United Air Lines 6% Notes Due 2028

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Voluntary retirement program

Voluntary retirement program

Voluntary leave of absence program

Voluntary leave of absence program

Involuntary severance programs

Continental Airlines Inc

United Continental Holdings Inc

United Continental Holdings Inc

Cleveland

Cleveland

Cleveland

Cleveland

Aircraft

Pilot Disability Plan

Departure

Weighted Average

Minimum

Maximum

Location

Operation

Merger, Acquisition, Integration Costs and Other Charges [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument stated interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.00%

8.00%

8.00%

'

6.00%

6.00%

6.00%

6.00%

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$88

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amount of senior notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

125

188

'

400

'

652

'

'

326

'

326

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument convertible effective interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.00%

'

8.00%

'

6.00%

'

'

6.00%

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument maturity year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2024

'

'2031

'

'

'2026

'

'2028

'

'

'

'

'

'

'

'

'

'

'

'

Debt extinguishment charge

'

'

'

'

'

'

'

'

'

'

'

309

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of liabilities extinguished

'

'

'

'

'

'

'

'

'

'

'

212

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Labor agreement costs

'

'

'

127

'

'

21

454

'

'

127

475

'

127

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

475

80

Number of fleet service, passenger service, storekeeper and pilot workgroups

'

'

1,200

'

'

'

'

'

'

'

1,200

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Severance and benefits

'

'

91

'

'

14

'

'

76

49

105

125

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

32

64

17

26

15

'

'

'

Number of mechanics offering to retire early

'

'

'

'

'

'

'

'

'

400

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of flight attendants voluntarily on leave

'

'

'

'

'

'

'

'

'

1,800

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of flight attendants accepted voluntary retirement

'

'

'

'

'

'

'

'

1,300

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Intangible asset impairment

'

'

'

'

'

'

'

'

'

'

1

30

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment charges of equipment held for disposal

'

'

'

'

'

'

'

'

'

'

32

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Temporary grounding of 787 aircraft charges

'

'

'

'

7

11

'

'

'

'

18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Termination of maintenance service contract

'

'

'

'

'

'

'

'

'

'

'

'

58

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Adjustment of reserves for certain legal matters

'

'

'

'

'

'

'

'

'

'

29

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accruals for future rent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11

'

'

'

'

'

'

Number of leased air craft

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4

'

'

'

'

'

'

Gain related to contract termination

'

'

'

'

'

'

'

'

'

'

5

'

-58

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss on sale of asset

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aircraft-related charges (gains), net

'

'

-1

-34

'

3

14

'

7

25

-32

46

-13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

46

'

'

Special revenue item

'

107

'

'

'

'

'

'

'

'

'

'

107

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of aircraft to be sold

30

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of aircraft that the company operate

'

'

'

'

'

'

'

'

'

'

'

133

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accelerated depreciation recorded on aircraft

'

'

'

'

'

'

'

'

'

'

$89

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Increase (decrease) in net income per basic share due to change in estimate

'

'

'

'

'

'

'

'

'

'

($0.26)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Increase (decrease) in net income per diluted share due to change in estimate

'

'

'

'

'

'

'

'

'

'

($0.23)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of flight reductions in average daily departures from Cleveland

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

60.00%

'

'

'

'

'

'

'

'

'

'

Reductions in number of peak day mainline departures

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

Number of peak day mainline departures

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

26

'

'

'

'

'

'

'

'

'

'

'

Percentage of flight reductions in regional departures from Cleveland

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

70.00%

'

'

'

'

'

'

'

'

'

Reductions in regional departures rate of increments in each of early April, May and June 2014

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.33

'

'

'

'

'

'

'

'

'

'

'

Number of peak day flights from Cleveland after reductions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

72

'

'

'

'

'

'

'

'

'

'

'

Number of destinations from Cleveland on non-stop basis

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20

'

'

'

'

'

'

'

'

'

'

'

Reductions in number airport operations and catering positions in Cleveland

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

470

'

'

'

'

'

'

'

'

Accrual_Activity_Detail

Accrual Activity (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Severance/ Medical Costs	'	'	'
Schedule Of Accrual Activity [Line Items]	'	'	'
Beginning Balance	$65	$55	$102
Accrual	120	170	21
Payments	-94	-160	-68
Ending Balance	91	65	55
Permanently Grounded Aircraft	'	'	'
Schedule Of Accrual Activity [Line Items]	'	'	'
Beginning Balance	5	31	41
Accrual	10	-1	5
Payments	-4	-25	-15
Ending Balance	$11	$5	$31

Operating_Revenue_by_Principle

Operating Revenue by Principle Geographic Region (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	$9,329	$10,228	$10,001	$8,721	$8,702	$9,909	$9,939	$8,602	$38,279	$37,152	$37,110
Domestic (U.S. and Canada)	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	22,092	21,276	21,922
Pacific	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	5,794	6,040	5,404
Atlantic	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	7,132	6,582	6,675
Latin America	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	3,261	3,254	3,109
United Airlines, Inc.	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	38,287	37,160	37,119
United Airlines, Inc. | Domestic (U.S. and Canada)	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	22,100	21,284	21,931
United Airlines, Inc. | Pacific	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	5,794	6,040	5,404
United Airlines, Inc. | Atlantic	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	7,132	6,582	6,675
United Airlines, Inc. | Latin America	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	$3,261	$3,254	$3,109

Schedule_of_Selected_Quarterly

Schedule of Selected Quarterly Financial Data (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Quarterly Financial Data [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Operating revenue	$9,329	$10,228	$10,001	$8,721	$8,702	$9,909	$9,939	$8,602	$38,279	$37,152	$37,110
Income (loss) from operations	235	508	770	-264	-465	200	575	-271	1,249	39	1,822
Net income (loss)	$140	$379	$469	($417)	($620)	$6	$339	($448)	$571	($723)	$840
Basic earnings (loss) per share	$0.39	$1.06	$1.37	($1.26)	($1.87)	$0.02	$1.02	($1.36)	$1.64	($2.18)	$2.54
Diluted earnings (loss) per share	$0.37	$0.98	$1.21	($1.26)	($1.87)	$0.02	$0.89	($1.36)	$1.53	($2.18)	$2.26

Schedule_of_Effect_of_Four_Qua

Schedule of Effect of Four Quarters Events (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Quarterly Financial Data [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Integration-related costs	$40	$50	$45	$70	$408	$60	$137	$134	$205	$739	$517
Labor agreement costs	'	127	'	'	21	454	'	'	127	475	'
Severance and benefits	91	'	'	14	'	'	76	49	105	125	'
Asset impairments	33	'	'	'	24	'	'	6	33	30	4
Additional costs associated with the temporarily grounded Boeing 787 aircraft	'	'	7	11	'	'	'	'	18	'	'
(Gains) losses on sale of assets and other special charges, net	1	34	'	-3	-14	'	-7	-25	32	-46	13
Total special items	165	211	52	92	439	514	206	164	'	'	'
Income tax benefit	-7	'	'	'	-9	'	'	-2	-32	-1	5
Total special items, net of tax	$158	$211	$52	$92	$430	$514	$206	$162	'	'	'

Valuation_and_Qualifying_Accou

Valuation and Qualifying Accounts (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Allowance for doubtful accounts	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Period	$13		$7		$6
Additions Charged to Costs and Expenses	35		12		8
Deductions	35	[1]	6	[1]	7	[1]
Balance at End of Period	13		13		7
Obsolescence allowance- spare parts	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Period	125		89		64
Additions Charged to Costs and Expenses	38		40		31
Deductions	1	[1]	4	[1]	6	[1]
Balance at End of Period	162		125		89
Valuation allowance for deferred tax assets	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Period	4,603		4,137		4,171
Additions Charged to Costs and Expenses	7		487		333
Deductions	888	[1]	21	[1]	367	[1]
Other	84	[2]	'		'
Balance at End of Period	3,806		4,603		4,137
United Airlines, Inc. | Allowance for doubtful accounts	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Period	13		7		6
Additions Charged to Costs and Expenses	35		12		8
Deductions	35	[1]	6	[1]	7	[1]
Balance at End of Period	13		13		7
United Airlines, Inc. | Obsolescence allowance- spare parts	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Period	125		89		64
Additions Charged to Costs and Expenses	38		40		31
Deductions	1	[1]	4	[1]	6	[1]
Balance at End of Period	162		125		89
United Airlines, Inc. | Valuation allowance for deferred tax assets	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Period	4,503		4,048		4,008
Additions Charged to Costs and Expenses	8		661		371
Deductions	898	[1]	206	[1]	331	[1]
Other	163	[2]	'		'
Balance at End of Period	$3,776		$4,503		$4,048
[1]	Deduction from reserve for purpose for which reserve was created.
[2]	See Note 7 to the financial statements included in Part II, Item 8 of this report for additional information related to other valuation allowance adjustments.