United Airlines (UAL) 10-Q 18 Apr 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 12, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	UAL
Entity Registrant Name	United Continental Holdings, Inc.
Entity Central Index Key	100,517
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		277,265,493
United Airlines, Inc.
Document Information [Line Items]
Entity Registrant Name	United Airlines, Inc.
Entity Central Index Key	319,687
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		1,000

Statements of Consolidated Oper

Statements of Consolidated Operations - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	[1]
Operating revenue:
Passenger revenue	$ 8,149	$ 7,653
Cargo	293	238
Other operating revenue	590	535
Total operating revenue	9,032	8,426
Operating expense:
Salaries and related costs	2,726	2,636
Aircraft fuel	1,965	1,560
Regional capacity purchase	619	536
Landing fees and other rent	558	544
Depreciation and amortization	541	518
Aircraft maintenance materials and outside repairs	440	454
Distribution expenses	342	319
Aircraft rent	127	179
Special charges (Note 10)	40	51
Other operating expenses	1,398	1,309
Total operating expenses	8,756	8,106
Operating income	276	320
Nonoperating income (expense):
Interest expense	(176)	(162)
Interest capitalized	19	23
Interest income	17	11
Miscellaneous, net	48	(42)
Total nonoperating expense, net	(92)	(170)
Income before income taxes	184	150
Income tax expense	37	51
Net income	$ 147	$ 99
Earnings per share, basic and diluted	$ 0.52	$ 0.32
United Airlines, Inc.
Operating revenue:
Passenger revenue	$ 8,149	$ 7,653
Cargo	293	238
Other operating revenue	590	535
Total operating revenue	9,032	8,426
Operating expense:
Salaries and related costs	2,726	2,636
Aircraft fuel	1,965	1,560
Regional capacity purchase	619	536
Landing fees and other rent	558	544
Depreciation and amortization	541	518
Aircraft maintenance materials and outside repairs	440	454
Distribution expenses	342	319
Aircraft rent	127	179
Special charges (Note 10)	40	51
Other operating expenses	1,397	1,309
Total operating expenses	8,755	8,106
Operating income	277	320
Nonoperating income (expense):
Interest expense	(176)	(162)
Interest capitalized	19	23
Interest income	17	11
Miscellaneous, net	48	(41)
Total nonoperating expense, net	(92)	(169)
Income before income taxes	185	151
Income tax expense	38	51
Net income	$ 147	$ 100
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	[1]
Net income	$ 147	$ 99
Other comprehensive income (loss), net change related to:
Employee benefit plans, net of taxes	30	(8)
Investments and other, net of taxes	3	1
Total other comprehensive income (loss), net	33	(7)
Total comprehensive income, net	180	92
United Airlines, Inc.
Net income	147	100
Other comprehensive income (loss), net change related to:
Employee benefit plans, net of taxes	30	(8)
Investments and other, net of taxes	3	1
Total other comprehensive income (loss), net	33	(7)
Total comprehensive income, net	$ 180	$ 93
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	[1]
Current assets:
Cash and cash equivalents	$ 2,404	$ 1,482
Short-term investments	2,071	2,316
Receivables, less allowance for doubtful accounts (2018 - $7; 2017 - $7)	1,760	1,340
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2018 - $365; 2017 - $354)	924	924
Prepaid expenses and other	1,128	1,071
Total current assets	8,287	7,133
Operating property and equipment: Owned-
Flight equipment	29,651	28,692
Other property and equipment	7,193	6,946
Total owned property and equipment	36,844	35,638
Less - Accumulated depreciation and amortization	(11,538)	(11,159)
Total owned property and equipment, net	25,306	24,479
Purchase deposits for flight equipment	1,025	1,344
Capital leases-
Flight equipment	1,205	1,151
Other property and equipment	11	11
Total capital leases	1,216	1,162
Less - Accumulated amortization	(808)	(777)
Total capital leases, net	408	385
Total operating property and equipment, net	26,739	26,208
Other assets:
Goodwill	4,523	4,523
Intangibles, less accumulated amortization (2018 - $1,329; 2017 - $1,313)	3,521	3,539
Restricted cash	95	91
Investments in affiliates and other, net	853	852
Total other assets	8,992	9,005
Total assets	44,018	42,346
Current liabilities:
Advance ticket sales	5,501	3,940
Accounts payable	2,399	2,196
Frequent flyer deferred revenue	2,221	2,192
Accrued salaries and benefits	1,637	2,166
Current maturities of long-term debt	1,655	1,565
Current maturities of capital leases	124	128
Other	646	576
Total current liabilities	14,183	12,763
Long-term debt	12,166	11,703
Long-term obligations under capital leases	1,019	996
Other liabilities and deferred credits:
Frequent flyer deferred revenue	2,716	2,591
Postretirement benefit liability	1,593	1,602
Pension liability	1,828	1,921
Deferred income taxes	250	204
Lease fair value adjustment, net	171	198
Other	1,756	1,634
Total other liabilities and deferred credits	8,314	8,150
Commitments and contingencies
Stockholders' equity:
Preferred stock
Common stock	3	3
Additional capital invested	6,077	6,098
Retained earnings	4,684	4,549
Stock held in treasury, at cost	(1,314)	(769)
Accumulated other comprehensive loss	(1,114)	(1,147)
Total stockholders' equity	8,336	8,734
Total liabilities and stockholders' equity	44,018	42,346
United Airlines, Inc.
Current assets:
Cash and cash equivalents	2,398	1,476
Short-term investments	2,071	2,316
Receivables, less allowance for doubtful accounts (2018 - $7; 2017 - $7)	1,760	1,340
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2018 - $365; 2017 - $354)	924	924
Prepaid expenses and other	1,129	1,071
Total current assets	8,282	7,127
Operating property and equipment: Owned-
Flight equipment	29,651	28,692
Other property and equipment	7,193	6,946
Total owned property and equipment	36,844	35,638
Less - Accumulated depreciation and amortization	(11,538)	(11,159)
Total owned property and equipment, net	25,306	24,479
Purchase deposits for flight equipment	1,025	1,344
Capital leases-
Flight equipment	1,205	1,151
Other property and equipment	11	11
Total capital leases	1,216	1,162
Less - Accumulated amortization	(808)	(777)
Total capital leases, net	408	385
Total operating property and equipment, net	26,739	26,208
Other assets:
Goodwill	4,523	4,523
Intangibles, less accumulated amortization (2018 - $1,329; 2017 - $1,313)	3,521	3,539
Restricted cash	95	91
Investments in affiliates and other, net	853	852
Total other assets	8,992	9,005
Total assets	44,013	42,340
Current liabilities:
Advance ticket sales	5,501	3,940
Accounts payable	2,399	2,196
Frequent flyer deferred revenue	2,221	2,192
Accrued salaries and benefits	1,637	2,166
Current maturities of long-term debt	1,655	1,565
Current maturities of capital leases	124	128
Other	652	581
Total current liabilities	14,189	12,768
Long-term debt	12,166	11,703
Long-term obligations under capital leases	1,019	996
Other liabilities and deferred credits:
Frequent flyer deferred revenue	2,716	2,591
Postretirement benefit liability	1,593	1,602
Pension liability	1,828	1,921
Deferred income taxes	277	231
Lease fair value adjustment, net	171	198
Other	1,756	1,634
Total other liabilities and deferred credits	8,341	8,177
Commitments and contingencies
Stockholders' equity:
Additional capital invested	1,233	1,787
Retained earnings	8,287	8,146
Accumulated other comprehensive loss	(1,114)	(1,147)
Receivable from related parties	(108)	(90)
Total stockholders' equity	8,298	8,696
Total liabilities and stockholders' equity	$ 44,013	$ 42,340
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	[1]
Receivables, allowance for doubtful accounts	$ 7	$ 7
Aircraft fuel, spare parts and supplies, obsolescence allowance	365	354
Intangibles, accumulated amortization	$ 1,329	$ 1,313
Common stock, par value	$ 0.01	$ 0.01
Common shares, authorized	1,000,000,000	1,000,000,000
Common shares, outstanding	279,410,451	286,973,195
United Airlines, Inc.
Receivables, allowance for doubtful accounts	$ 7	$ 7
Aircraft fuel, spare parts and supplies, obsolescence allowance	365	354
Intangibles, accumulated amortization	$ 1,329	$ 1,313
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
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Statements of Consolidated Cash

Statements of Consolidated Cash Flows - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Cash Flows from Operating Activities:
Net cash provided by operating activities		$ 1,733	$ 547
Cash Flows from Investing Activities:
Capital expenditures		(979)	(691)
Purchases of short-term and other investments		(596)	(774)
Proceeds from sale of short-term and other investments		840	810
Proceeds from sale of property and equipment		3	4
Other, net		2	8
Net cash used in investing activities		(730)	(643)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt and airport construction financing		696	755
Repurchases of common stock		(529)	(258)
Payments of long-term debt		(189)	(315)
Principal payments under capital leases		(30)	(31)
Other, net		(32)	(65)
Net cash provided (used) in financing activities		(84)	86
Net increase (decrease) in cash, cash equivalents and restricted cash		919	(10)
Cash, cash equivalents and restricted cash at beginning of the period		1,591	2,303
Cash, cash equivalents and restricted cash at end of the period	[1]	2,510	2,293
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt and capital leases		74	711
Airport construction financing		12	21
United Airlines, Inc.
Cash Flows from Operating Activities:
Net cash provided by operating activities		1,717	535
Cash Flows from Investing Activities:
Capital expenditures		(979)	(691)
Purchases of short-term investments and other investments		(596)	(774)
Proceeds from sale of short-term and other investments		840	810
Proceeds from sale of property and equipment		3	4
Other, net		2	8
Net cash used in investing activities		(730)	(643)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt and airport construction financing		696	755
Dividend to UAL		(529)	(258)
Payments of long-term debt		(189)	(315)
Principal payments under capital leases		(30)	(31)
Other, net		(16)	(53)
Net cash provided (used) in financing activities		(68)	98
Net increase (decrease) in cash, cash equivalents and restricted cash		919	(10)
Cash, cash equivalents and restricted cash at beginning of the period		1,585	2,297
Cash, cash equivalents and restricted cash at end of the period	[2]	2,504	2,287
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt and capital leases		74	711
Airport construction financing		$ 12	$ 21
[1]	The following table provides a reconciliation of cash, cash equivalents and restricted cash to amounts reported within the consolidated balance sheet: Reconciliation of cash, cash equivalents and restricted cash: Current assets: Cash and cash equivalents $ 2,404 $ 2,164 Restricted cash included in Prepaid expenses and other 11 - Other assets: Restricted cash 95 129 Total cash, cash equivalents and restricted cash $ 2,510 $ 2,293
[2]	The following table provides a reconciliation of cash, cash equivalents and restricted cash to amounts reported within the consolidated balance sheet: Reconciliation of cash, cash equivalents and restricted cash: Current assets: Cash and cash equivalents $ 2,398 $ 2,158 Restricted cash included in Prepaid expenses and other 11 - Other assets: Restricted cash 95 129 Total cash, cash equivalents and restricted cash $ 2,504 $ 2,287

Statements of Consolidated Cas7

Statements of Consolidated Cash Flows (Parenthetical) $ in Millions	Mar. 31, 2018USD ($)
Current assets:
Cash and cash equivalents	$ 2,404
Other assets:
Restricted cash	95
Total cash, cash equivalents and restricted cash	2,510	[1]
United Airlines, Inc.
Current assets:
Cash and cash equivalents	2,398
Other assets:
Restricted cash	95
Total cash, cash equivalents and restricted cash	2,504	[2]
Prepaid Expenses and Other
Current assets:
Restricted cash included in Prepaid expenses and other	11
Prepaid Expenses and Other | United Airlines, Inc.
Current assets:
Restricted cash included in Prepaid expenses and other	$ 11
[1]	The following table provides a reconciliation of cash, cash equivalents and restricted cash to amounts reported within the consolidated balance sheet: Reconciliation of cash, cash equivalents and restricted cash: Current assets: Cash and cash equivalents $ 2,404 $ 2,164 Restricted cash included in Prepaid expenses and other 11 - Other assets: Restricted cash 95 129 Total cash, cash equivalents and restricted cash $ 2,510 $ 2,293
[2]	The following table provides a reconciliation of cash, cash equivalents and restricted cash to amounts reported within the consolidated balance sheet: Reconciliation of cash, cash equivalents and restricted cash: Current assets: Cash and cash equivalents $ 2,398 $ 2,158 Restricted cash included in Prepaid expenses and other 11 - Other assets: Restricted cash 95 129 Total cash, cash equivalents and restricted cash $ 2,504 $ 2,287

Recently Issued Accounting Stan

Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2018
Recently Issued Accounting Standards	NOTE 1 - RECENTLY ISSUED ACCOUNTING STANDARDS The Company adopted FASB Accounting Standards Codification Topic 606, Revenue from Contracts with Customers The Company adopted Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost 10-Q The new standards had the same impact on the financial statements of United as they had on the financial statements of UAL. The table below presents the impact of the adoption of the New Revenue Standard and the New Retirement Standard on select accounts and captions of the statement of consolidated operations for the first quarter of 2017 (in millions, except per share amounts): Three Months Ended March 31, 2017 As New New As Passenger revenue $ 7,174 $ 479 $ — $ 7,653 Cargo 220 18 — 238 Other operating revenue 1,026 (491) — 535 Total operating revenue 8,420 6 — 8,426 Salaries and related costs 2,661 — (25) 2,636 Distribution expenses 307 12 — 319 Other operating expenses 1,332 (23) — 1,309 Total operating expenses 8,142 (11) (25) 8,106 Operating income 278 17 25 320 Interest expense (150) (12) — (162) Miscellaneous, net (17) — (25) (42) Total nonoperating expense, net (133) (12) (25) (170) Income before income taxes 145 5 — 150 Income tax expense 49 2 — 51 Net income 96 3 — 99 Earnings per share, basic and diluted 0.31 0.01 — 0.32 The table below presents the impact of the adoption of the New Revenue Standard on UAL’s balance sheet accounts and captions as of December 31, 2017 (in millions): At December 31, 2017 As New Revenue Adjustments As Prepaid expenses and other $ 1,051 $ 20 $ 1,071 Total current assets 7,113 20 7,133 Total assets 42,326 20 42,346 Advance ticket sales 3,876 64 3,940 Frequent flyer deferred revenue 2,176 16 2,192 Other 569 7 576 Total current liabilities 12,676 87 12,763 Frequent flyer deferred revenue - long-term 2,565 26 2,591 Deferred income taxes 225 (21) 204 Total other liabilities and deferred credits 8,145 5 8,150 Retained earnings 4,621 (72 ) 4,549 Total stockholders’ equity 8,806 (72) 8,734 Total liabilities and stockholders’ equity 42,326 20 42,346 The Company adopted Accounting Standards Update No. 2016-01, Financial Instruments—Overall 825-10) 2016-01”) available-for-sale Accounting for Leases. Leases right-of-use Leases

Revenue

Revenue	3 Months Ended
	Mar. 31, 2018
Revenue	NOTE 2 - REVENUE The Company presents Passenger revenue, Cargo revenue and Other operating revenue on its income statement. Passenger revenue is recognized when transportation is provided and Cargo revenue is recognized when shipments are delivered. Other operating revenue is recognized as the related performance obligations are satisfied. The Company sells passenger ticket and related ancillary services for mainline and regional flights primarily via credit cards with payments collected by the Company in advance of the performance of related services. The Company initially records ticket sales in its Advance ticket sales liability, deferring revenue recognition until the travel occurs. For travel that has more than one flight segment, the Company deems each segment as a separate performance obligation and recognizes revenue for each segment as travel occurs. Tickets sold by other airlines where the Company provides the transportation are recognized as passenger revenue at the estimated value to be billed to the other airline when travel is provided. 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 its billings and payables with other airlines based on historical experience. The Company sells certain tickets with connecting flights with one or more segments operated by its other airline partners. For segments operated by its other airline partners, the Company has determined that it is acting as an agent on behalf of the other airlines as they are responsible for their portion of the contract (i.e. transportation of the passenger). The Company, as the agent, recognizes revenue within Other operating revenue at the time of the travel for the net amount representing commission to be retained by the Company for any segments flown by other airlines. Refundable tickets expire after one year from the date of issuance. Non-refundable tickets to non-refundable tickets United initially capitalizes the costs of selling airline travel tickets and then recognizes those costs as Distribution expense at the time of travel. Passenger ticket costs include credit card fees, travel agency and other commissions paid, as well as global distribution systems booking fees. Ticket Taxes. Accounts Receivable. non-airline Advance Ticket Sales. Frequent Flyer Accounting. of non-airline partners. and non-travel awards. Miles Earned in Conjunction with Travel. non-travel The Company’s estimated selling price of miles is based on an equivalent ticket value less breakage, which incorporates the expected redemption of miles, as the best estimate of selling price for these miles. The equivalent ticket value 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, loyalty status and geographic region. The estimated selling price of miles is adjusted by breakage that considers a number of factors, including redemption patterns of various customer groups. The Company reviews its breakage estimates annually based upon the latest available information regarding redemption and expiration patterns. 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 program. Co-Brand co-branded co-brand • MileagePlus miles awarded - United has a performance obligation to provide MileagePlus cardholders with miles to be used for air travel and non-travel non-travel non-travel • Marketing - United’s performance obligation is to provide Chase access to its customer list and the use of its brand. United determined access to its customer list and use of the United brand constitute a single performance obligation by virtue of being highly interdependent and interrelated. Marketing revenue is recorded to Other operating revenue over the term of the co-brand • Advertising - United has a performance obligation to provide advertising in support of the MileagePlus card in various customer contact points such as United’s website, email promotions, direct mail campaigns, airport advertising and in-flight • Other travel-related benefits - United’s performance obligations are comprised of various items such as waived bag fees, seat upgrades, and lounge passes. Lounge passes are recorded to Other operating revenue as customers use the lounge passes. Bag fees and seat upgrades are recorded to Passenger revenue at the time of the associated travel. The fair value of the separately identifiable performance obligations is determined using management’s estimated selling price of each component. 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 co-brand Frequent flyer deferred revenue. Three Months Ended 2018 2017 Total Frequent flyer deferred revenue—beginning balance $ 4,783 $ 4,889 Total miles awarded 603 488 Travel miles redeemed (Passenger revenue) (409) (398) Non-travel (40) (39) Total Frequent flyer deferred revenue—ending balance $ 4,937 $ 4,940 In the three months ended March 31, 2018 and 2017, the Company recognized, in Other operating revenue, $482 million and $403 million, respectively, related to the marketing, advertising and other travel-related benefits of the mileage revenue associated with our various partner agreements including, but not limited to, our Chase co-brand non-travel Passenger Revenue by Geography. 2018 2017 Mainline $ 3,485 $ 3,272 Regional 1,483 1,379 Domestic 4,968 4,651 Atlantic 1,252 1,117 Pacific 1,069 1,053 Latin America 860 832 International 3,181 3,002 Consolidated $ 8,149 $ 7,653 Mainline 6,616 6,227 Regional 1,533 1,426 Consolidated $ 8,149 $ 7,653 Ancillary Fees.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share	NOTE 3 - EARNINGS PER SHARE The computations of UAL’s basic and diluted earnings per share are set forth below (in millions, except per share amounts): Three Months Ended 2018 2017 Earnings available to common stockholders $ 147 $ 99 Basic weighted-average shares outstanding 283.9 313.7 Effect of employee stock awards 1.0 0.9 Diluted weighted-average shares outstanding 284.9 314.6 Earnings per share, basic and diluted $ 0.52 $ 0.32 The number of antidilutive securities excluded from the computation of diluted earnings per share amounts was not material. In the three months ended March 31, 2018, UAL repurchased approximately 8.4 million shares of UAL common stock in open market transactions for $0.6 billion. As of March 31, 2018, the Company had approximately $2.4 billion remaining to purchase shares under its share repurchase program. UAL may repurchase shares through the open market, privately negotiated transactions, block trades or accelerated share repurchase transactions from time to time in accordance with applicable securities laws. UAL will repurchase shares of UAL common stock subject to prevailing market conditions, and may discontinue such repurchases at any time. See Part II, Item 2, Unregistered Sales of Equity Securities and Use of Proceeds of this report for additional information.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss)	NOTE 4 - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The tables below present the components of the Company’s accumulated other comprehensive income (loss), net of tax (“AOCI”) (in millions): UAL Pension and Investments and Income Taxes Total Balance at December 31, 2017 $ (1,102) $ (6) $ (39) $ (1,147) Changes in value 23 (4) (6) 13 Amounts reclassified to earnings 16 — (3) 13 Amounts reclassified to retained earnings (a) — 7 — 7 Net change 39 3 (9) 33 Balance at March 31, 2018 $ (1,063) $ (3) $ (48) $ (1,114) Balance at December 31, 2016 $ (854) $ (1) $ 26 $ (829) Changes in value (26) — 10 (16) Amounts reclassified to earnings 13 2 (6) 9 Net change (13) 2 4 (7) Balance at March 31, 2017 $ (867) $ 1 $ 30 $ (836) (a) This amount represents the unrealized loss on the Company’s investment in Azul, S.A. (“Azul”) which was previously classified as an available-for-sale Details for AOCI Components Reclassified to Income Three Months Ended Affected Line Item in the Statements of Consolidated Operations 2018 2017 Pension and other postretirement liabilities Amortization of unrecognized losses and prior service cost (a) $ 16 $ 13 Miscellaneous, net Investments and Other Reclassifications of losses into earnings related to fuel derivative contracts — 2 Aircraft fuel (a) This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 5 to the financial statements included in this Part I, Item 1 for additional information).

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Taxes	NOTE 5 - INCOME TAXES The Company’s effective tax rate for the three months ended March 31, 2018 and 2017 was 20.3% and 33.6%, respectively. The effective tax rate represents a blend of federal, state and foreign taxes and included the impact of certain nondeductible items. The effective tax rate for the three months ended March 31, 2018 also reflects the reduced federal corporate income tax rate as a result of the enactment of the Tax Cuts and Jobs Act (the “Tax Act”) in December 2017 and the impact of a change in the Company’s mix of domestic and foreign earnings. We continue to analyze the different aspects of the Tax Act which could potentially affect the provisional estimates that were recorded at December 31, 2017.

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2018
Employee Benefit Plans	NOTE 6 - EMPLOYEE BENEFIT PLANS Defined Benefit Pension and Other Postretirement Benefit Plans. Pension Benefits Other Postretirement Benefits Affected Line Item Consolidated Operations 2018 2017 2018 2017 Service cost $ 57 $ 49 $ 3 $ 2 Salaries and related costs Interest cost 54 55 15 17 Miscellaneous, net Expected return on plan assets (73) (60) — — Miscellaneous, net Amortization of unrecognized (gain) loss and prior service cost (credit) 33 31 (17) (18) Miscellaneous, net Settlement loss — 1 — — Miscellaneous, net Total $ 71 $ 76 $ 1 $ 1 During the three months ended March 31, 2018, the Company contributed $113 million to its U.S. domestic tax-qualified Share-Based Compensation. pro-rata, 20-day pre-tax 20-day The table below presents information related to share-based compensation (in millions): Three Months Ended 2018 2017 Share-based compensation expense $ 17 $ 23 March 31, 2018 December 31, 2017 Unrecognized share-based compensation $ 102 $ 53

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Financial Instruments and Fair Value Measurements	NOTE 7 - FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS The table below presents disclosures about the financial assets and liabilities measured at fair value on a recurring basis in UAL’s financial statements (in millions): March 31, 2018 December 31, 2017 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 2,404 $ 2,404 $ — $ — $ 1,482 $ 1,482 $ — $ — Short-term investments: Corporate debt 945 — 945 — 958 — 958 — Asset-backed securities 606 — 606 — 753 — 753 — U.S. government and agency notes 110 — 110 — 113 — 113 — Certificates of deposit placed through an account registry service (“CDARS”) 53 — 53 — 120 — 120 — Other fixed-income securities 172 — 172 — 188 — 188 — Other investments measured at net asset value (“NAV”) 185 — — — 184 — — — Restricted cash 106 106 — — 109 109 — — Long-term investments: Equity securities 144 144 — — 99 99 — — Enhanced equipment trust certificates (“EETC”) 19 — — 19 22 — — 22 Available-for-sale available-for-sale, Restricted cash Equity securities Investments presented in the table 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 (in millions): Fair Value of Debt by Fair Value Hierarchy Level March 31, 2018 December 31, 2017 Carrying Fair Value Carrying Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Long-term debt $ 13,821 $ 14,068 $ — $ 10,377 $ 3,691 $ 13,268 $ 13,787 $ — $ 10,115 $ 3,672 Fair value of the financial instruments included in the tables above 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, Equity securities, EETC 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, or (c) broker quotes obtained by third-party valuation services. Other investments measured at NAV In accordance with the relevant accounting standards, certain investments that are measured at fair value using the NAV per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table above are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. The investments measured using NAV are shares of mutual funds that invest in fixed-income instruments including bonds, debt securities, and other similar instruments issued by various U.S. and non-U.S. three-day Long-term 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.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies	NOTE 8 - COMMITMENTS Commitments. Aircraft Type Number of Firm Airbus A350 45 Boeing 737 MAX 161 Boeing 777-300ER 2 Boeing 787 14 (a) United also has options and purchase rights for additional aircraft. The aircraft listed in the table above are scheduled for delivery through 2027. To the extent the Company and the aircraft manufacturers with whom the Company has existing orders for new aircraft agree to modify the contracts governing those orders, the amount and timing of the Company’s future capital commitments could change. For the remainder of 2018, United expects to take delivery of two Boeing 777-300ER Boeing 767-300ER aircraft. The table below summarizes United’s commitments as of March 31, 2018, which primarily relate to the acquisition of aircraft and related spare engines, aircraft improvements and include other capital purchase commitments. Any new firm aircraft orders, including through the exercise of purchase options and purchase rights, will increase the total future capital commitments of the Company. (in billions) Last nine months of 2018 $ 2.4 2019 3.7 2020 2.0 2021 2.7 2022 1.8 After 2022 9.8 $ 22.4 Facility and Other Operating Leases. The table below summarizes the Company’s scheduled future minimum lease payments under facility operating leases having initial or remaining noncancelable lease terms of more than one year as of March 31, 2018 (in millions): Facility and Other Last nine months of 2018 $ 1,010 2019 1,209 2020 1,302 2021 1,068 2022 930 After 2022 7,576 $ 13,095 Guarantees. tax-exempt Increased Cost Provisions. non-U.S. non-U.S. As of March 31, 2018, United is the guarantor of $154 million of aircraft mortgage debt issued by one of United’s regional carriers. The aircraft mortgage debt is subject to similar increased cost provisions as described above for the Company’s debt, and the Company would potentially be responsible for those costs under the guarantees. Labor Negotiations.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt	NOTE 9 - DEBT As of March 31, 2018, a substantial portion of the Company’s assets, principally aircraft, route authorities, airport slots and loyalty program intangible assets, was pledged under various loan and other agreements. As of March 31, 2018, UAL and United were in compliance with their respective debt covenants. As of March 31, 2018, United had its entire capacity of $2.0 billion available under the revolving credit facility of the Company’s Amended and Restated Credit and Guaranty Agreement (as amended, the “2017 Credit Agreement”). EETCs . EETC Date Class Principal Final expected Stated Total proceeds received from issuance of debt during 2018 and recorded as debt as of March 31, 2018 Remaining proceeds from issuance of debt to be received in future periods February 2018 AA $ 677 March 2030 3.50% $ 476 $ 201 February 2018 A 258 March 2030 3.70% 181 77 $ 935 $ 657 $ 278 The table below presents the Company’s contractual principal payments (not including debt discount or debt issuance costs) at March 31, 2018 under then-outstanding long-term debt agreements (in millions): Last nine months of 2018 $ 1,380 2019 1,218 2020 1,207 2021 1,194 2022 1,529 After 2022 7,457 $ 13,985

Special Charges

Special Charges	3 Months Ended
	Mar. 31, 2018
Special Charges	NOTE 10 - SPECIAL CHARGES For the three months ended March 31, special charges consisted of the following (in millions): Three Months Ended Operating: 2018 2017 Severance and benefit costs $ 14 $ 37 Impairment of assets 23 — (Gains) losses on sale of assets and other special charges 3 14 Special charges 40 51 Income tax benefit related to special charges (9) (18) Total special charges, net of tax $ 31 $ 33 During the three months ended March 31, 2018 and 2017, the Company recorded severance and benefit costs related to a voluntary early-out During the three months ended March 31, 2018, the Company recorded a $23 million ($17 million net of taxes) fair value adjustment for aircraft purchased off lease and impairments related to certain fleet types and certain international slots no longer in use. Accrual Activity The severance-related accrual as of March 31, 2018 is primarily related to severance and other compensation expense associated with voluntary employee early retirement programs and is expected to be mostly paid through early 2019. The accrual balance for future lease payments on permanently grounded aircraft as of March 31, 2018 is expected to be mostly paid through 2025. Activity related to these accruals is as follows (in millions): Severance and Permanently Balance at December 31, 2017 $ 37 $ 22 Accrual 14 — Payments (19) (1) Balance at March 31, 2018 $ 32 $ 21 Severance and Permanently Balance at December 31, 2016 $ 14 $ 41 Accrual 37 — Payments (23) (1) Balance at March 31, 2017 $ 28 $ 40

Recently Issued Accounting St18

Recently Issued Accounting Standards (Tables)	3 Months Ended
	Mar. 31, 2018
ASC 606
Schedule of Adoption of Accounting Standards and Expected Impact on Financial Statements	The table below presents the impact of the adoption of the New Revenue Standard and the New Retirement Standard on select accounts and captions of the statement of consolidated operations for the first quarter of 2017 (in millions, except per share amounts): Three Months Ended March 31, 2017 As New New As Passenger revenue $ 7,174 $ 479 $ — $ 7,653 Cargo 220 18 — 238 Other operating revenue 1,026 (491) — 535 Total operating revenue 8,420 6 — 8,426 Salaries and related costs 2,661 — (25) 2,636 Distribution expenses 307 12 — 319 Other operating expenses 1,332 (23) — 1,309 Total operating expenses 8,142 (11) (25) 8,106 Operating income 278 17 25 320 Interest expense (150) (12) — (162) Miscellaneous, net (17) — (25) (42) Total nonoperating expense, net (133) (12) (25) (170) Income before income taxes 145 5 — 150 Income tax expense 49 2 — 51 Net income 96 3 — 99 Earnings per share, basic and diluted 0.31 0.01 — 0.32 The table below presents the impact of the adoption of the New Revenue Standard on UAL’s balance sheet accounts and captions as of December 31, 2017 (in millions): At December 31, 2017 As New Revenue Adjustments As Prepaid expenses and other $ 1,051 $ 20 $ 1,071 Total current assets 7,113 20 7,133 Total assets 42,326 20 42,346 Advance ticket sales 3,876 64 3,940 Frequent flyer deferred revenue 2,176 16 2,192 Other 569 7 576 Total current liabilities 12,676 87 12,763 Frequent flyer deferred revenue - long-term 2,565 26 2,591 Deferred income taxes 225 (21) 204 Total other liabilities and deferred credits 8,145 5 8,150 Retained earnings 4,621 (72 ) 4,549 Total stockholders’ equity 8,806 (72) 8,734 Total liabilities and stockholders’ equity 42,326 20 42,346

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Summary of Roll Forward of Frequent Flyer Deferred Revenue	The table below presents a roll forward of Frequent flyer deferred revenue (in millions): Three Months Ended 2018 2017 Total Frequent flyer deferred revenue—beginning balance $ 4,783 $ 4,889 Total miles awarded 603 488 Travel miles redeemed (Passenger revenue) (409) (398) Non-travel (40) (39) Total Frequent flyer deferred revenue—ending balance $ 4,937 $ 4,940
Summary of Passenger Revenue by Geographic Region and by Mainline Versus Regional	The following table presents passenger revenue by geographic region and by mainline versus regional for the three months ended March 31 (in millions): 2018 2017 Mainline $ 3,485 $ 3,272 Regional 1,483 1,379 Domestic 4,968 4,651 Atlantic 1,252 1,117 Pacific 1,069 1,053 Latin America 860 832 International 3,181 3,002 Consolidated $ 8,149 $ 7,653 Mainline 6,616 6,227 Regional 1,533 1,426 Consolidated $ 8,149 $ 7,653

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Computation of Earnings Per Share	The computations of UAL’s basic and diluted earnings per share are set forth below (in millions, except per share amounts): Three Months Ended 2018 2017 Earnings available to common stockholders $ 147 $ 99 Basic weighted-average shares outstanding 283.9 313.7 Effect of employee stock awards 1.0 0.9 Diluted weighted-average shares outstanding 284.9 314.6 Earnings per share, basic and diluted $ 0.52 $ 0.32

Accumulated Other Comprehensi21

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2018
Components of Accumulated Other Comprehensive Income, Net of Tax	The tables below present the components of the Company’s accumulated other comprehensive income (loss), net of tax (“AOCI”) (in millions): UAL Pension and Investments and Income Taxes Total Balance at December 31, 2017 $ (1,102) $ (6) $ (39) $ (1,147) Changes in value 23 (4) (6) 13 Amounts reclassified to earnings 16 — (3) 13 Amounts reclassified to retained earnings (a) — 7 — 7 Net change 39 3 (9) 33 Balance at March 31, 2018 $ (1,063) $ (3) $ (48) $ (1,114) Balance at December 31, 2016 $ (854) $ (1) $ 26 $ (829) Changes in value (26) — 10 (16) Amounts reclassified to earnings 13 2 (6) 9 Net change (13) 2 4 (7) Balance at March 31, 2017 $ (867) $ 1 $ 30 $ (836) (a) This amount represents the unrealized loss on the Company’s investment in Azul, S.A. (“Azul”) which was previously classified as an available-for-sale

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Components of Net Periodic Benefit Cost	The Company’s net periodic benefit cost includes the following components for the three months ended March 31 (in millions): Pension Benefits Other Postretirement Benefits Affected Line Item Consolidated Operations 2018 2017 2018 2017 Service cost $ 57 $ 49 $ 3 $ 2 Salaries and related costs Interest cost 54 55 15 17 Miscellaneous, net Expected return on plan assets (73) (60) — — Miscellaneous, net Amortization of unrecognized (gain) loss and prior service cost (credit) 33 31 (17) (18) Miscellaneous, net Settlement loss — 1 — — Miscellaneous, net Total $ 71 $ 76 $ 1 $ 1
Share-Based Compensation Expense	The table below presents information related to share-based compensation (in millions): Three Months Ended 2018 2017 Share-based compensation expense $ 17 $ 23 March 31, 2018 December 31, 2017 Unrecognized share-based compensation $ 102 $ 53

Financial Instruments and Fai23

Financial Instruments and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents disclosures about the financial assets and liabilities measured at fair value on a recurring basis in UAL’s financial statements (in millions): March 31, 2018 December 31, 2017 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 2,404 $ 2,404 $ — $ — $ 1,482 $ 1,482 $ — $ — Short-term investments: Corporate debt 945 — 945 — 958 — 958 — Asset-backed securities 606 — 606 — 753 — 753 — U.S. government and agency notes 110 — 110 — 113 — 113 — Certificates of deposit placed through an account registry service (“CDARS”) 53 — 53 — 120 — 120 — Other fixed-income securities 172 — 172 — 188 — 188 — Other investments measured at net asset value (“NAV”) 185 — — — 184 — — — Restricted cash 106 106 — — 109 109 — — Long-term investments: Equity securities 144 144 — — 99 99 — — Enhanced equipment trust certificates (“EETC”) 19 — — 19 22 — — 22
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 (in millions): Fair Value of Debt by Fair Value Hierarchy Level March 31, 2018 December 31, 2017 Carrying Fair Value Carrying Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Long-term debt $ 13,821 $ 14,068 $ — $ 10,377 $ 3,691 $ 13,268 $ 13,787 $ — $ 10,115 $ 3,672

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Commitments to Purchase Aircrafts	As of March 31, 2018, United had firm commitments and options to purchase aircraft from The Boeing Company (“Boeing”) and Airbus S.A.S. (“Airbus”) presented in the table below: Aircraft Type Number of Firm Airbus A350 45 Boeing 737 MAX 161 Boeing 777-300ER 2 Boeing 787 14 (a) United also has options and purchase rights for additional aircraft.
Future Minimum Lease Payments for Operating Leases	The table below summarizes the Company’s scheduled future minimum lease payments under facility operating leases having initial or remaining noncancelable lease terms of more than one year as of March 31, 2018 (in millions): Facility and Other Last nine months of 2018 $ 1,010 2019 1,209 2020 1,302 2021 1,068 2022 930 After 2022 7,576 $ 13,095
Aircraft Type
Schedule of Commitments to Purchase Aircrafts	The table below summarizes United’s commitments as of March 31, 2018, which primarily relate to the acquisition of aircraft and related spare engines, aircraft improvements and include other capital purchase commitments. Any new firm aircraft orders, including through the exercise of purchase options and purchase rights, will increase the total future capital commitments of the Company. (in billions) Last nine months of 2018 $ 2.4 2019 3.7 2020 2.0 2021 2.7 2022 1.8 After 2022 9.8 $ 22.4

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Details of Pass Through Trusts	Certain details of the pass-through trusts with proceeds received from issuance of debt in 2018 are as follows (in millions, except stated interest rate): EETC Date Class Principal Final expected Stated Total proceeds received from issuance of debt during 2018 and recorded as debt as of March 31, 2018 Remaining proceeds from issuance of debt to be received in future periods February 2018 AA $ 677 March 2030 3.50% $ 476 $ 201 February 2018 A 258 March 2030 3.70% 181 77 $ 935 $ 657 $ 278
Contractual Principal Payments	The table below presents the Company’s contractual principal payments (not including debt discount or debt issuance costs) at March 31, 2018 under then-outstanding long-term debt agreements (in millions): Last nine months of 2018 $ 1,380 2019 1,218 2020 1,207 2021 1,194 2022 1,529 After 2022 7,457 $ 13,985

Special Charges (Tables)

Special Charges (Tables)	3 Months Ended
	Mar. 31, 2018
Components of Special charges	For the three months ended March 31, special charges consisted of the following (in millions): Three Months Ended Operating: 2018 2017 Severance and benefit costs $ 14 $ 37 Impairment of assets 23 — (Gains) losses on sale of assets and other special charges 3 14 Special charges 40 51 Income tax benefit related to special charges (9) (18) Total special charges, net of tax $ 31 $ 33
Accrual Activity	Activity related to these accruals is as follows (in millions): Severance and Permanently Balance at December 31, 2017 $ 37 $ 22 Accrual 14 — Payments (19) (1) Balance at March 31, 2018 $ 32 $ 21 Severance and Permanently Balance at December 31, 2016 $ 14 $ 41 Accrual 37 — Payments (23) (1) Balance at March 31, 2017 $ 28 $ 40

Schedule of Adoption of ASC 606

Schedule of Adoption of ASC 606 and Expected Impact - Statements of Consolidated Operations (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Passenger revenue	$ 8,149	$ 7,653	[1]
Cargo	293	238	[1]
Other operating revenue	590	535	[1]
Total operating revenue	9,032	8,426	[1]
Salaries and related costs	2,726	2,636	[1]
Distribution expenses	342	319	[1]
Other operating expenses	1,398	1,309	[1]
Total operating expenses	8,756	8,106	[1]
Operating income	276	320	[1]
Interest expense	(176)	(162)	[1]
Miscellaneous, net	48	(42)	[1]
Total nonoperating expense, net	(92)	(170)	[1]
Income before income taxes	184	150	[1]
Income tax expense	37	51	[1]
Net income	$ 147	$ 99	[1]
Earnings per share, basic and diluted	$ 0.52	$ 0.32	[1]
ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Passenger revenue		$ 7,653
Cargo		238
Other operating revenue		535
Total operating revenue		8,426
Salaries and related costs		2,636
Distribution expenses		319
Other operating expenses		1,309
Total operating expenses		8,106
Operating income		320
Interest expense		(162)
Miscellaneous, net		(42)
Total nonoperating expense, net		(170)
Income before income taxes		150
Income tax expense		51
Net income		$ 99
Earnings per share, basic and diluted		$ 0.32
Scenario, Previously Reported | ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Passenger revenue		$ 7,174
Cargo		220
Other operating revenue		1,026
Total operating revenue		8,420
Salaries and related costs		2,661
Distribution expenses		307
Other operating expenses		1,332
Total operating expenses		8,142
Operating income		278
Interest expense		(150)
Miscellaneous, net		(17)
Total nonoperating expense, net		(133)
Income before income taxes		145
Income tax expense		49
Net income		$ 96
Earnings per share, basic and diluted		$ 0.31
Adjustment | ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Passenger revenue		$ 479
Cargo		18
Other operating revenue		(491)
Total operating revenue		6
Distribution expenses		12
Other operating expenses		(23)
Total operating expenses		(11)
Operating income		17
Interest expense		(12)
Total nonoperating expense, net		(12)
Income before income taxes		5
Income tax expense		2
Net income		$ 3
Earnings per share, basic and diluted		$ 0.01
New Retirement Standard Adjustments | ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Salaries and related costs		$ (25)
Total operating expenses		(25)
Operating income		25
Miscellaneous, net		(25)
Total nonoperating expense, net		$ (25)
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Schedule of Adoption of ASC 628

Schedule of Adoption of ASC 606 and Expected Impact - Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Item Effected [Line Items]
Prepaid expenses and other	$ 1,128	$ 1,071	[1]
Total current assets	8,287	7,133	[1]
Total assets	44,018	42,346	[1]
Advance ticket sales	5,501	3,940	[1]
Frequent flyer deferred revenue	2,221	2,192	[1]
Other	646	576	[1]
Total current liabilities	14,183	12,763	[1]
Frequent flyer deferred revenue - long-term	2,716	2,591	[1]
Deferred income taxes	250	204	[1]
Total other liabilities and deferred credits	8,314	8,150	[1]
Retained earnings	4,684	4,549	[1]
Total stockholders' equity	8,336	8,734	[1]
Total liabilities and stockholders' equity	$ 44,018	42,346	[1]
ASC 606
Item Effected [Line Items]
Prepaid expenses and other		1,071
Total current assets		7,133
Total assets		42,346
Advance ticket sales		3,940
Frequent flyer deferred revenue		2,192
Other		576
Total current liabilities		12,763
Frequent flyer deferred revenue - long-term		2,591
Deferred income taxes		204
Total other liabilities and deferred credits		8,150
Retained earnings		4,549
Total stockholders' equity		8,734
Total liabilities and stockholders' equity		42,346
Scenario, Previously Reported | ASC 606
Item Effected [Line Items]
Prepaid expenses and other		1,051
Total current assets		7,113
Total assets		42,326
Advance ticket sales		3,876
Frequent flyer deferred revenue		2,176
Other		569
Total current liabilities		12,676
Frequent flyer deferred revenue - long-term		2,565
Deferred income taxes		225
Total other liabilities and deferred credits		8,145
Retained earnings		4,621
Total stockholders' equity		8,806
Total liabilities and stockholders' equity		42,326
Adjustment | ASC 606
Item Effected [Line Items]
Prepaid expenses and other		20
Total current assets		20
Total assets		20
Advance ticket sales		64
Frequent flyer deferred revenue		16
Other		7
Total current liabilities		87
Frequent flyer deferred revenue - long-term		26
Deferred income taxes		(21)
Total other liabilities and deferred credits		5
Retained earnings		(72)
Total stockholders' equity		(72)
Total liabilities and stockholders' equity		$ 20
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Deferred Revenue Arrangement [Line Items]
Passenger revenue	$ 8,149	$ 7,653	[1]
Frequent flyer mileage program expiration period after member account inactivity	18 months
Frequent flyer mileage program period in which miles redeemed	4 years
Other operating revenue	$ 590	535	[1]
Costs associated with non-travel miles redeemed	28	28
Chase and Other Partner Agreements
Deferred Revenue Arrangement [Line Items]
Other operating revenue	482	403
Deferred Revenue for Miles in Loyalty Program
Deferred Revenue Arrangement [Line Items]
Passenger revenue	$ 1,900	1,900
Minimum
Deferred Revenue Arrangement [Line Items]
Frequent flyer mileage program expiration period	1 year
Maximum
Deferred Revenue Arrangement [Line Items]
Frequent flyer mileage program expiration period	8 years
Passenger Revenue
Deferred Revenue Arrangement [Line Items]
Ancillary fees	$ 497	$ 478
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Summary of Roll Forward of Freq

Summary of Roll Forward of Frequent Flyer Deferred Revenue (Detail) - Deferred Revenue for Miles in Loyalty Program - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Deferred Revenue Arrangement [Line Items]
Total Frequent flyer deferred revenue-beginning balance	$ 4,783	$ 4,889
Total miles awarded	603	488
Travel miles redeemed (Passenger revenue)	(409)	(398)
Non-travel miles redeemed (Other operating revenue)	(40)	(39)
Total Frequent flyer deferred revenue-ending balance	$ 4,937	$ 4,940

Summary of Passenger Revenue by

Summary of Passenger Revenue by Geographic Region and by Mainline Versus Regional (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Deferred Revenue Arrangement [Line Items]
Passenger-Mainline	$ 6,616	$ 6,227
Passenger-Regional	1,533	1,426
Total passenger revenue	8,149	7,653	[1]
International
Deferred Revenue Arrangement [Line Items]
Total passenger revenue	3,181	3,002
Domestic
Deferred Revenue Arrangement [Line Items]
Passenger-Mainline	3,485	3,272
Passenger-Regional	1,483	1,379
Total passenger revenue	4,968	4,651
Atlantic | International
Deferred Revenue Arrangement [Line Items]
Total passenger revenue	1,252	1,117
Pacific | International
Deferred Revenue Arrangement [Line Items]
Total passenger revenue	1,069	1,053
Latin America | International
Deferred Revenue Arrangement [Line Items]
Total passenger revenue	$ 860	$ 832
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Computation of Earnings Per Sha

Computation of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Computation of Earnings Per Share [Line Items]
Earnings available to common stockholders	$ 147	$ 99
Basic weighted-average shares outstanding	283.9	313.7
Effect of employee stock awards	1	0.9
Diluted weighted-average shares outstanding	284.9	314.6
Earnings per share, basic and diluted	$ 0.52	$ 0.32	[1]
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) shares in Millions, $ in Billions	3 Months Ended
	Mar. 31, 2018USD ($)shares
Earnings Loss Per Share [Line Items]
Amount remaining under repurchase programs	$ 2.4
Open Market Repurchase Program
Earnings Loss Per Share [Line Items]
Number of shares repurchased | shares	8.4
Repurchases of common stock	$ 0.6

Components of Accumulated Other

Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, income taxes		$ (39)	$ 26
Changes in value, income taxes		(6)	10
Amounts reclassified to earnings, income taxes		(3)	(6)
Amounts reclassified to retained earnings, income taxes	[1]	0
Net change, income taxes		(9)	4
Ending Balance, income taxes		(48)	30
Beginning Balance, net of tax	[2]	8,734
Changes in value, net of tax		13	(16)
Amounts reclassified to earnings, net of tax		13
Amounts reclassified to retained earnings, net of tax	[1]	7
Total other comprehensive income (loss), net		33	(7)	[3]
Ending Balance, net of tax		8,336
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, net of tax		(1,147)	(829)
Amounts reclassified to earnings, net of tax			9
Ending Balance, net of tax		(1,114)	(836)
Pension and Other Postretirement Liabilities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, before tax		(1,102)	(854)
Changes in value, before tax		23	(26)
Amounts reclassified to earnings, before tax		16	13
Net change, before tax		39	(13)
Ending Balance, before tax		(1,063)	(867)
Investments and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, before tax		(6)	(1)
Changes in value, before tax		(4)
Amounts reclassified to earnings, before tax			2
Amounts reclassified to retained earnings, before tax	[1]	7
Net change, before tax		3	2
Ending Balance, before tax		$ (3)	$ 1
[1]	This amount represents the unrealized loss on the Company's investment in Azul, S.A. ("Azul") which was previously classified as an available-for-sale security.
[2]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.
[3]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Details about Accumulated Other

Details about Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Miscellaneous, Net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of unrecognized losses and prior service cost	[1]	$ 16	$ 13
Fuel Oil Contract | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications of losses into earnings related to fuel derivative contracts			$ 2
[1]	This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 5 to the financial statements included in this Part I, Item 1 for additional information).

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Taxes [Line Items]
Effective income tax rate	20.30%	33.60%

Components of Net Periodic Bene

Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 57	$ 49
Interest cost	54	55
Expected return on plan assets	(73)	(60)
Amortization of unrecognized (gain) loss and prior service cost (credit)	33	31
Settlement loss		1
Total	71	76
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	2
Interest cost	15	17
Amortization of unrecognized (gain) loss and prior service cost (credit)	(17)	(18)
Total	$ 1	$ 1

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)shares
Pension Benefits
Compensation and Retirement Disclosure [Abstract]
Employer contribution to tax-qualified defined benefit pension plans | $	$ 113
RSUs
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, option awards granted	1.7
Share-based compensation, vesting period	3 years
Performance Shares
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, vesting period	3 years
Share-Based Compensation, vesting date	Dec. 31, 2020
Number of days used to compute performance period average closing price of restricted stock units	20 days
Time Vested Restricted Stock Units RSU
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, other than options, awards granted	1
Performance Based Restricted Stock Units RSU
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, other than options, awards granted	0.7

Share-Based Compensation Expens

Share-Based Compensation Expense (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share-based compensation expense	$ 17	$ 23
Unrecognized share-based compensation	$ 102	$ 53

Financial Assets and Liabilitie

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 2,404	$ 1,482
Restricted cash	106	109
Equity securities	144	99
Enhanced equipment trust certificates ("EETC")	19	22
Corporate Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	945	958
Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	606	753
U.S. Government and Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	110	113
CDARS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	53	120
Other Fixed Income Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	172	188
Other Investments Measured At NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	185	184
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	2,404	1,482
Restricted cash	106	109
Equity securities	144	99
Level 2 | Corporate Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	945	958
Level 2 | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	606	753
Level 2 | U.S. Government and Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	110	113
Level 2 | CDARS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	53	120
Level 2 | Other Fixed Income Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	172	188
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Enhanced equipment trust certificates ("EETC")	$ 19	$ 22

Financial Instruments and Fai41

Financial Instruments and Fair Value Measurements - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018
EETC
Fair Value [Line Items]
Available-for-sale securities remaining maturities	2,019
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	17 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	3 years
CDARS | Maximum
Fair Value [Line Items]
Available-for-sale securities remaining maturities	1 year
U.S. Government and Other Securities | Minimum
Fair Value [Line Items]
Available-for-sale securities remaining maturities	1 year
U.S. Government and Other Securities | Maximum
Fair Value [Line Items]
Available-for-sale securities remaining maturities	3 years

Carrying Values and Estimated F

Carrying Values and Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Carrying (Reported) Amount, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 13,821	$ 13,268
Estimate of Fair Value, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt fair value	14,068	13,787
Estimate of Fair Value, Fair Value Disclosure | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt fair value	10,377	10,115
Estimate of Fair Value, Fair Value Disclosure | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt fair value	$ 3,691	$ 3,672

Schedule of Commitments to Purc

Schedule of Commitments to Purchase Aircrafts (Detail) - United Airlines, Inc. - Capital Addition Purchase Commitments	Mar. 31, 2018Aircraft	[1]
Airbus A350 Aircraft
Long-term Purchase Commitment [Line Items]
Number of new aircraft committed to purchase	45
Boeing 737 MAX Aircraft
Long-term Purchase Commitment [Line Items]
Number of new aircraft committed to purchase	161
Boeing 777-300ER Aircraft
Long-term Purchase Commitment [Line Items]
Number of new aircraft committed to purchase	2
Boeing 787 Aircraft
Long-term Purchase Commitment [Line Items]
Number of new aircraft committed to purchase	14
[1]	United also has options and purchase rights for additional aircraft.

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)Aircraft
Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure	$ 2,000,000,000
Operating leases obligations	1,400,000,000
Capital leases obligations	454,000,000
Floating Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount	3,400,000,000
Fixed Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount	52,000,000
Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Aggregate balance	3,300,000,000
Aircraft Mortgage Debt
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure	154,000,000
Facility and Other Operating Leases
Commitments and Contingencies [Line Items]
Operating leases obligations	$ 13,095,000,000
Maximum
Commitments and Contingencies [Line Items]
Debt instrument, remaining terms (years)	11 years
Maximum | Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Debt instrument maturity year	2,038
Maximum | Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Debt instrument, remaining terms (years)	11 years
Minimum | Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Debt instrument maturity year	2,019
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Debt instrument principal amount	$ 935,000,000
Number of employees	90,800
Percentage of employees represented by various U.S. labor organizations	79.00%
Boeing 777-300ER Aircraft
Commitments and Contingencies [Line Items]
Number of aircrafts expects to take delivery | Aircraft	2
Boeing 787 Aircraft
Commitments and Contingencies [Line Items]
Number of aircrafts expects to take delivery | Aircraft	3
Boeing 737 MAX Aircraft
Commitments and Contingencies [Line Items]
Number of aircrafts expects to take delivery | Aircraft	10
Boeing 767-300ER Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2018 | Aircraft	3
Chicago O'Hare International Airport | Facility and Other Operating Leases
Commitments and Contingencies [Line Items]
Operating lease agreement term	15 years
Operating lease description	A lease term of approximately 15 years effective May 12, 2018 through December 31, 2033.
Airbus A319 Aircraft
Commitments and Contingencies [Line Items]
Number of new aircraft committed to purchase | Aircraft	20
Airbus A319 Aircraft | Maximum
Commitments and Contingencies [Line Items]
Expected delivery date scheduled, Year	2,021
Airbus A319 Aircraft | Minimum
Commitments and Contingencies [Line Items]
Expected delivery date scheduled, Year	2,020

Schedule of Acquisition of Airc

Schedule of Acquisition of Aircrafts and Related Spare Engines (Detail) $ in Billions	Mar. 31, 2018USD ($)
Unrecorded Unconditional Purchase Obligation [Line Items]
Last nine months of 2018	$ 2.4
2,019	3.7
2,020	2
2,021	2.7
2,022	1.8
After 2,022	9.8
Total commitments	$ 22.4

Future Minimum Lease Payments f

Future Minimum Lease Payments for Operating Leases (Detail) - Facility and Other Operating Leases $ in Millions	Mar. 31, 2018USD ($)
Schedule Of Future Minimum Rental Payments For Operating Leases [Line Items]
Last nine months of 2018	$ 1,010
2,019	1,209
2,020	1,302
2,021	1,068
2,022	930
After 2,022	7,576
Contractual Obligation, Total	$ 13,095

Debt - Additional Information (

Debt - Additional Information (Detail) $ in Billions	Mar. 31, 2018USD ($)
United Airlines, Inc. | Secured Debt | Revolving Credit Facility
Debt Instrument [Line Items]
Available under revolving credit facility	$ 2

Details of Pass Through Trusts

Details of Pass Through Trusts (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Total proceeds received from issuance of debt during 2018 and recorded as debt	$ 696	$ 755
United Airlines, Inc.
Debt Instrument [Line Items]
Principal	935
Total proceeds received from issuance of debt during 2018 and recorded as debt	696	$ 755
United Airlines, Inc. | February Twenty Eighteen [Member]
Debt Instrument [Line Items]
Total proceeds received from issuance of debt during 2018 and recorded as debt	657
Remaining proceeds from issuance of debt to be received in future periods	278
United Airlines, Inc. | Class AA Pass Through Certificates | February Twenty Eighteen [Member]
Debt Instrument [Line Items]
Principal	$ 677
Final expected distribution date	2030-03
Stated interest rate	3.50%
Total proceeds received from issuance of debt during 2018 and recorded as debt	$ 476
Remaining proceeds from issuance of debt to be received in future periods	201
United Airlines, Inc. | Class A Pass Through Certificates | February Twenty Eighteen [Member]
Debt Instrument [Line Items]
Principal	$ 258
Final expected distribution date	2030-03
Stated interest rate	3.70%
Total proceeds received from issuance of debt during 2018 and recorded as debt	$ 181
Remaining proceeds from issuance of debt to be received in future periods	$ 77

Contractual Principal Payments

Contractual Principal Payments (Detail) - UAL and United $ in Millions	Mar. 31, 2018USD ($)
Debt Instrument [Line Items]
Last nine months of 2018	$ 1,380
2,019	1,218
2,020	1,207
2,021	1,194
2,022	1,529
After 2,022	7,457
Long-term debt	$ 13,985

Components of Special Charges (

Components of Special Charges (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating:
Severance and benefit costs	$ 14	$ 37
Impairment of assets	23
(Gains) losses on sale of assets and other special charges	3	14
Special charges	40	51	[1]
Income tax benefit related to special charges	(9)	(18)
Total special charges, net of tax	$ 31	$ 33
[1]	Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

Special Charges - Additional In

Special Charges - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)Technician
Special Charges [Line Items]
Severance and benefits costs	$ 14,000,000	$ 37,000,000
Fair value adjustment for aircraft purchased	23,000,000
Fair value adjustment for aircraft purchased, net of taxes	$ 17,000,000
Severance-related accrual expected payment date	2,019
Grounded aircraft related accrual expected payment date	2,025
International Brotherhood of Teamsters
Special Charges [Line Items]
Severance and benefits costs	$ 8,000,000	21,000,000
Severance and benefits costs net of tax	7,000,000	$ 14,000,000
Voluntary early out program | International Brotherhood of Teamsters
Special Charges [Line Items]
Number of positions eliminated | Technician		1,000
Voluntary early out program | International Brotherhood of Teamsters | Maximum
Special Charges [Line Items]
Severance payment per participant		$ 100,000
Management Reorganization Initiative
Special Charges [Line Items]
Severance and benefits costs	6,000,000	16,000,000
Severance and benefits costs net of tax	$ 4,000,000	$ 10,000,000

Schedule of Severance Related A

Schedule of Severance Related Accrual (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Severance and Benefits Costs
Schedule Of Accrual Activity [Line Items]
Beginning Balance	$ 37	$ 14
Accrual	14	37
Payments	(19)	(23)
Ending Balance	32	28
Permanently Grounded Aircraft
Schedule Of Accrual Activity [Line Items]
Beginning Balance	22	41
Payments	(1)	(1)
Ending Balance	$ 21	$ 40