United Airlines (UAL) 10-Q 19 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 12, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
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		296,252,435
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		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating revenue:
Passenger-Mainline	$ 7,083	$ 7,017	$ 19,970	$ 19,119
Passenger-Regional	1,445	1,586	4,354	4,577
Total passenger revenue	8,528	8,603	24,324	23,696
Cargo	257	224	731	626
Other operating revenue	1,093	1,086	3,243	3,182
Total operating revenue	9,878	9,913	28,298	27,504
Operating expense:
Salaries and related costs	2,812	2,625	8,341	7,707
Aircraft fuel	1,809	1,603	5,038	4,258
Landing fees and other rent	585	546	1,670	1,612
Regional capacity purchase	567	572	1,652	1,645
Depreciation and amortization	556	503	1,610	1,473
Aircraft maintenance materials and outside repairs	451	451	1,377	1,301
Distribution expenses	352	345	1,021	987
Aircraft rent	145	168	476	521
Special charges (Note 10)	50	45	145	669
Other operating expenses	1,459	1,431	4,199	3,998
Total operating expenses	8,786	8,289	25,529	24,171
Operating income	1,092	1,624	2,769	3,333
Nonoperating income (expense):
Interest expense	(164)	(150)	(472)	(466)
Interest capitalized	20	20	64	48
Interest income	17	14	41	31
Miscellaneous, net (Note 10)	15	2	(3)	(11)
Total nonoperating expense, net	(112)	(114)	(370)	(398)
Income before income taxes	980	1,510	2,399	2,935
Income tax expense	343	545	848	1,069
Net income	$ 637	$ 965	$ 1,551	$ 1,866
Earnings per share, basic	$ 2.12	$ 3.02	$ 5.06	$ 5.57
Earnings per share, diluted	$ 2.12	$ 3.01	$ 5.04	$ 5.57
United Airlines, Inc.
Operating revenue:
Passenger-Mainline	$ 7,083	$ 7,017	$ 19,970	$ 19,119
Passenger-Regional	1,445	1,586	4,354	4,577
Total passenger revenue	8,528	8,603	24,324	23,696
Cargo	257	224	731	626
Other operating revenue	1,093	1,086	3,243	3,182
Total operating revenue	9,878	9,913	28,298	27,504
Operating expense:
Salaries and related costs	2,812	2,625	8,341	7,707
Aircraft fuel	1,809	1,603	5,038	4,258
Landing fees and other rent	585	546	1,670	1,612
Regional capacity purchase	567	572	1,652	1,645
Depreciation and amortization	556	503	1,610	1,473
Aircraft maintenance materials and outside repairs	451	451	1,377	1,301
Distribution expenses	352	345	1,021	987
Aircraft rent	145	168	476	521
Special charges (Note 10)	50	45	145	669
Other operating expenses	1,459	1,431	4,198	3,997
Total operating expenses	8,786	8,289	25,528	24,170
Operating income	1,092	1,624	2,770	3,334
Nonoperating income (expense):
Interest expense	(164)	(150)	(472)	(466)
Interest capitalized	20	20	64	48
Interest income	17	14	41	31
Miscellaneous, net (Note 10)	15	2	(3)	(11)
Total nonoperating expense, net	(112)	(114)	(370)	(398)
Income before income taxes	980	1,510	2,400	2,936
Income tax expense	343	545	848	1,069
Net income	$ 637	$ 965	$ 1,552	$ 1,867

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income	$ 637	$ 965	$ 1,551	$ 1,866
Other comprehensive income (loss), net change related to:
Fuel derivative financial instruments, net of taxes		12	1	123
Employee benefit plans, net of taxes	3	(75)	(1)	(89)
Investments and other, net of taxes	17	(1)	5	(1)
Total other comprehensive income (loss), net	20	(64)	5	33
Total comprehensive income, net	657	901	1,556	1,899
United Airlines, Inc.
Net income	637	965	1,552	1,867
Other comprehensive income (loss), net change related to:
Fuel derivative financial instruments, net of taxes		12	1	123
Employee benefit plans, net of taxes	3	(75)	(1)	(89)
Investments and other, net of taxes	17	(1)	5	(1)
Total other comprehensive income (loss), net	20	(64)	5	33
Total comprehensive income, net	$ 657	$ 901	$ 1,557	$ 1,900

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 1,870	$ 2,179
Short-term investments	2,458	2,249
Receivables, less allowance for doubtful accounts (2017 - $11; 2016 - $10)	1,603	1,176
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2017 - $342; 2016 - $295)	937	873
Prepaid expenses and other	1,009	832
Total current assets	7,877	7,309
Operating property and equipment: Owned-
Flight equipment	29,043	25,873
Other property and equipment	6,186	5,652
Total owned property and equipment	35,229	31,525
Less - Accumulated depreciation and amortization	(11,358)	(9,975)
Total owned property and equipment, net	23,871	21,550
Purchase deposits for flight equipment	1,044	1,059
Capital leases-
Flight equipment	1,136	1,319
Other property and equipment	488	331
Total capital leases	1,624	1,650
Less - Accumulated amortization	(910)	(941)
Total capital leases, net	714	709
Total operating property and equipment, net	25,629	23,318
Other assets:
Goodwill	4,523	4,523
Intangibles, less accumulated amortization (2017 - $1,294; 2016 - $1,234)	3,558	3,632
Deferred income taxes		655
Restricted cash	96	124
Investments in affiliates and other, net	882	579
Total other assets	9,059	9,513
Total assets	42,565	40,140
Current liabilities:
Advance ticket sales	4,537	3,730
Accounts payable	2,231	2,139
Frequent flyer deferred revenue	1,992	2,135
Accrued salaries and benefits	1,983	2,307
Current maturities of long-term debt	1,516	849
Current maturities of capital leases	125	116
Other	703	1,010
Total current liabilities	13,087	12,286
Long-term debt	11,334	9,918
Long-term obligations under capital leases	968	822
Other liabilities and deferred credits:
Frequent flyer deferred revenue	2,793	2,748
Postretirement benefit liability	1,588	1,581
Pension liability	1,631	1,892
Deferred income taxes	253
Advanced purchase of miles	106	430
Lease fair value adjustment, net	219	277
Other	1,616	1,527
Total other liabilities and deferred credits	8,206	8,455
Commitments and contingencies
Stockholder's equity:
Preferred stock
Common stock	3	3
Additional capital invested	6,591	6,569
Retained earnings	4,991	3,427
Stock held in treasury, at cost	(1,791)	(511)
Accumulated other comprehensive loss	(824)	(829)
Total stockholder's equity	8,970	8,659
Total liabilities and stockholder's equity	42,565	40,140
United Airlines, Inc.
Current assets:
Cash and cash equivalents	1,864	2,173
Short-term investments	2,458	2,249
Receivables, less allowance for doubtful accounts (2017 - $11; 2016 - $10)	1,603	1,176
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2017 - $342; 2016 - $295)	937	873
Prepaid expenses and other	1,008	832
Total current assets	7,870	7,303
Operating property and equipment: Owned-
Flight equipment	29,043	25,873
Other property and equipment	6,186	5,652
Total owned property and equipment	35,229	31,525
Less - Accumulated depreciation and amortization	(11,358)	(9,975)
Total owned property and equipment, net	23,871	21,550
Purchase deposits for flight equipment	1,044	1,059
Capital leases-
Flight equipment	1,136	1,319
Other property and equipment	488	331
Total capital leases	1,624	1,650
Less - Accumulated amortization	(910)	(941)
Total capital leases, net	714	709
Total operating property and equipment, net	25,629	23,318
Other assets:
Goodwill	4,523	4,523
Intangibles, less accumulated amortization (2017 - $1,294; 2016 - $1,234)	3,558	3,632
Deferred income taxes		612
Restricted cash	96	124
Investments in affiliates and other, net	882	579
Total other assets	9,059	9,470
Total assets	42,558	40,091
Current liabilities:
Advance ticket sales	4,537	3,730
Accounts payable	2,231	2,144
Frequent flyer deferred revenue	1,992	2,135
Accrued salaries and benefits	1,983	2,307
Current maturities of long-term debt	1,516	849
Current maturities of capital leases	125	116
Other	707	1,009
Total current liabilities	13,091	12,290
Long-term debt	11,334	9,918
Long-term obligations under capital leases	968	822
Other liabilities and deferred credits:
Frequent flyer deferred revenue	2,793	2,748
Postretirement benefit liability	1,588	1,581
Pension liability	1,631	1,892
Deferred income taxes	297
Advanced purchase of miles	106	430
Lease fair value adjustment, net	219	277
Other	1,616	1,527
Total other liabilities and deferred credits	8,250	8,455
Commitments and contingencies
Stockholder's equity:
Additional capital invested	2,325	3,573
Retained earnings	7,504	5,937
Accumulated other comprehensive loss	(824)	(829)
Receivable from related parties	(90)	(75)
Total stockholder's equity	8,915	8,606
Total liabilities and stockholder's equity	$ 42,558	$ 40,091

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Receivables, allowance for doubtful accounts	$ 11	$ 10
Aircraft fuel, spare parts and supplies, obsolescence allowance	342	295
Intangibles, accumulated amortization	$ 1,294	$ 1,234
Common stock, par value	$ 0.01	$ 0.01
Common shares, authorized	1,000,000,000	1,000,000,000
Common shares, outstanding	296,252,431	314,612,744
United Airlines, Inc.
Receivables, allowance for doubtful accounts	$ 11	$ 10
Aircraft fuel, spare parts and supplies, obsolescence allowance	342	295
Intangibles, accumulated amortization	$ 1,294	$ 1,234
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

Condensed Statements of Consoli

Condensed Statements of Consolidated Cash Flows - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net cash provided by operating activities		$ 2,685	$ 4,884
Cash Flows from Investing Activities:
Capital expenditures		(2,900)	(2,343)
Purchases of short-term and other investments		(2,584)	(1,989)
Proceeds from sale of short-term and other investments		2,380	1,957
Proceeds from sale of property and equipment		8	24
Investment in and loans to affiliates			(8)
Other, net		142	(5)
Net cash used in investing activities		(2,954)	(2,364)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt and airport construction financing		2,119	510
Repurchases of common stock		(1,291)	(2,442)
Payments of long-term debt		(722)	(911)
Principal payments under capital leases		(84)	(95)
Other, net		(77)	(40)
Net cash used in financing activities		(55)	(2,978)
Net decrease in cash, cash equivalents and restricted cash		(324)	(458)
Cash, cash equivalents and restricted cash at beginning of the period		2,303	3,212
Cash, cash equivalents and restricted cash at end of the period	[1]	1,979	2,754
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt and capital leases		918	115
Airport construction financing		41	68
Operating lease conversions to capital lease			12
United Airlines, Inc.
Cash Flows from Operating Activities:
Net cash provided by operating activities		2,671	4,878
Cash Flows from Investing Activities:
Capital expenditures		(2,900)	(2,343)
Purchases of short-term investments and other investments		(2,584)	(1,989)
Proceeds from sale of short-term and other investments		2,380	1,957
Proceeds from sale of property and equipment		8	24
Investment in and loans to affiliates			(8)
Other, net		142	(5)
Net cash used in investing activities		(2,954)	(2,364)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt and airport construction financing		2,119	510
Dividend to UAL		(1,291)	(2,442)
Payments of long-term debt		(722)	(911)
Principal payments under capital leases		(84)	(95)
Other, net		(63)	(34)
Net cash used in financing activities		(41)	(2,972)
Net decrease in cash, cash equivalents and restricted cash		(324)	(458)
Cash, cash equivalents and restricted cash at beginning of the period		2,297	3,206
Cash, cash equivalents and restricted cash at end of the period	[2]	1,973	2,748
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt and capital leases		918	115
Airport construction financing		$ 41	68
Operating lease conversions to capital lease			$ 12
[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 $ 1,870 $ 2,630 Restricted cash included in Prepaid expenses and other 13 1 Other assets: Restricted cash 96 123 Total cash, cash equivalents and restricted cash $ 1,979 $ 2,754
[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 $ 1,864 $ 2,624 Restricted cash included in Prepaid expenses and other 13 1 Other assets: Restricted cash 96 123 Total cash, cash equivalents and restricted cash $ 1,973 $ 2,748

Condensed Statements of Consol7

Condensed Statements of Consolidated Cash Flows (Parenthetical) - USD ($) $ in Millions		Sep. 30, 2017	Sep. 30, 2016
Current assets:
Cash and cash equivalents		$ 1,870	$ 2,630
Other assets:
Restricted cash		96	123
Total cash, cash equivalents and restricted cash	[1]	1,979	2,754
United Airlines, Inc.
Current assets:
Cash and cash equivalents		1,864	2,624
Other assets:
Restricted cash		96	123
Total cash, cash equivalents and restricted cash	[2]	1,973	2,748
Prepaid Expenses and Other
Current assets:
Restricted cash included in Prepaid expenses and other		13	1
Prepaid Expenses and Other | United Airlines, Inc.
Current assets:
Restricted cash included in Prepaid expenses and other		$ 13	$ 1
[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 $ 1,870 $ 2,630 Restricted cash included in Prepaid expenses and other 13 1 Other assets: Restricted cash 96 123 Total cash, cash equivalents and restricted cash $ 1,979 $ 2,754
[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 $ 1,864 $ 2,624 Restricted cash included in Prepaid expenses and other 13 1 Other assets: Restricted cash 96 123 Total cash, cash equivalents and restricted cash $ 1,973 $ 2,748

Recently Issued Accounting Stan

Recently Issued Accounting Standards	9 Months Ended
	Sep. 30, 2017
Recently Issued Accounting Standards	NOTE 1 - RECENTLY ISSUED ACCOUNTING STANDARDS The Financial Accounting Standards Board (“FASB”) amended the FASB Accounting Standards Codification and created a new Topic 606, Revenue from Contracts with Customers. Revenue Recognition In February 2016, the FASB amended the FASB Accounting Standards Codification and created a new Topic 842, Leases right-of-use Leases In January 2016, the FASB issued Accounting Standards Update No. 2016-01, Financial Instruments—Overall 825-10) 2016-01”). available-for-sale 2016-01 In March 2017, the FASB issued Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost 2017-07”). . 2017-07 2017-07

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share	NOTE 2 - EARNINGS The computations of UAL’s basic and diluted earnings per share are set forth below (in millions, except per share amounts): Three Months Ended Nine Months Ended 2017 2016 2017 2016 Earnings available to common stockholders $ 637 $ 965 $ 1,551 $ 1,866 Basic weighted-average shares outstanding 299.8 320.0 306.8 334.9 Effect of employee stock awards 0.8 0.4 0.8 0.3 Diluted weighted-average shares outstanding 300.6 320.4 307.6 335.2 Earnings per share, basic $ 2.12 $ 3.02 $ 5.06 $ 5.57 Earnings per share, diluted $ 2.12 $ 3.01 $ 5.04 $ 5.57 The number of antidilutive securities excluded from the computation of diluted earnings per share amounts was not material. In the three and nine months ended September 30, 2017, UAL repurchased approximately 8 million and 18 million shares of UAL common stock in open market transactions, respectively, for $0.6 billion and $1.3 billion, respectively. As of September 30, 2017, the Company had approximately $0.6 billion remaining to purchase shares under its existing share repurchase authority. 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)	9 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss)	NOTE 3 - ACCUMULATED The tables below present the components of the Company’s accumulated other comprehensive income (loss), net of tax (“AOCI”) (in millions): Deferred Taxes UAL Pension and Fuel Investments Pension and Fuel Investments Total Balance at June 30, 2017 $ (860) $ — $ (16) $ 26 $ — $ 6 $ (844) Changes in value (9) — 26 3 — (9) 11 Amounts reclassified to earnings 14 — — (5) — — 9 Net change 5 — 26 (2) — (9) 20 Balance at September 30, 2017 $ (855) $ — $ 10 $ 24 $ — $ (3) $ (824) Balance at December 31, 2016 $ (854) $ (2) $ 1 $ 24 $ 1 $ 1 $ (829) Changes in value (42) — 9 15 — (3) (21) Amounts reclassified to earnings 41 2 — (15) (1) (1) 26 Net change (1) 2 9 — (1) (4) 5 Balance at September 30, 2017 $ (855) $ — $ 10 $ 24 $ — $ (3) $ (824) Deferred Taxes UAL Pension and Fuel Investments Pension and Fuel Investments Total Balance at June 30, 2016 $ (385) $ (41) $ 3 $ (146) $ (165) $ — $ (734) Changes in value (124) (6) 1 45 2 (1) (83) Amounts reclassified to earnings 6 24 (2) (2) (8) 1 19 Net change (118) 18 (1) 43 (6) — (64) Balance at September 30, 2016 $ (503) $ (23) $ 2 $ (103) $ (171) $ — $ (798) Balance at December 31, 2015 $ (363) $ (215) $ 3 $ (154) $ (102) $ — $ (831) Changes in value (157) (5) 1 57 2 (1) (103) Amounts reclassified to earnings 17 197 (2) (6) (71) 1 136 Net change (140) 192 (1) 51 (69) — 33 Balance at September 30, 2016 $ (503) $ (23) $ 2 $ (103) $ (171) $ — $ (798) Details about AOCI Components Amount Reclassified from AOCI to Income Affected Line Item in the Statements of Consolidated Operations Three Months Ended Nine Months Ended 2017 2016 2017 2016 Pension and other postretirement liabilities Amortization of unrecognized losses and prior service cost (a) $ 14 $ 6 $ 41 $ 17 Salaries and related costs Fuel derivative contracts Reclassifications of losses into earnings — 24 2 197 Aircraft fuel Investments and other Reclassifications of gains into earnings — (2) — (2) Miscellaneous, net (a) This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 5 of this report for additional information).

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Taxes	NOTE 4 - INCOME TAXES The Company’s effective tax rate for the three and nine months ended September 30, 2017 was 35.0% and 35.3%, respectively, and the effective tax rate for the three and nine months ended September 30, 2016 was 36.1% and 36.4%, respectively. The effective tax rates represented a blend of federal, state and foreign taxes and included the impact of certain nondeductible items. The effective tax rate for the three and nine months ended September 30, 2017 also reflects the impact of a change in the mix of domestic and foreign earnings.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2017
Employee Benefit Plans	NOTE 5 - EMPLOYEE BENEFIT PLANS Defined Benefit Pension and Other Postretirement Benefit Plans. Pension Benefits Other Postretirement Three Months Ended September 30, Three Months Ended September 30, 2017 2016 2017 2016 Service cost $ 48 $ 29 $ 4 $ 4 Interest cost 55 50 16 22 Expected return on plan assets (61) (54) — — Amortization of unrecognized (gain) loss and prior service cost (credit) 32 19 (18) (13) Settlement loss 3 2 — — Curtailment gain — — — (47) Total $ 77 $ 46 $ 2 $ (34) Pension Benefits Other Postretirement Nine Months Ended Nine Months Ended 2017 2016 2017 2016 Service cost $ 146 $ 84 $ 10 $ 14 Interest cost 165 151 50 66 Expected return on plan assets (182) (162) (1) (1) Amortization of unrecognized (gain) loss and prior service cost (credit) 95 57 (54) (40) Settlement loss 5 4 — — Curtailment gain — — — (47) Total $ 229 $ 134 $ 5 $ (8) During the three and nine months ended September 30, 2017, the Company contributed $160 million and $400 million, respectively, to its U.S. domestic tax-qualified Share-Based Compensation. non-qualified In the nine months ended September 30, 2017, UAL granted share-based compensation awards pursuant to both the 2008 Plan and the 2017 Plan. These share-based compensation awards include 1.5 million RSUs, consisting of 0.9 million time-vested RSUs and 0.6 million performance-based RSUs, and 36,000 stock options. The time-vested RSUs vest pro-rata, 20-day pre-tax 20-day The table below presents information related to share-based compensation (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Share-based compensation expense $ 10 $ 23 $ 66 $ 36 September 30, December 31, Unrecognized share-based compensation $ 90 $ 65

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Financial Instruments and Fair Value Measurements	NOTE 6 - FINANCIAL 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): September 30, 2017 December 31, 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 1,870 $ 1,870 $ — $ — $ 2,179 $ 2,179 $ — $ — Short-term investments: Corporate debt 959 — 959 — 835 — 835 — Asset-backed securities 891 — 891 — 792 — 792 — Certificates of deposit placed through an account registry service (“CDARS”) 142 — 142 — 246 — 246 — U.S. government and agency notes 112 — 112 — 140 — 140 — Other fixed-income securities 171 — 171 — 54 — 54 — Other investments measured at NAV 183 — — — 182 — — — Restricted cash 109 109 — — 124 124 — — Long-term investments: Equity securities 114 114 — — — — — — Enhanced equipment trust certificates (“EETC”) 21 — — 21 23 — — 23 Available-for-sale available-for-sale. Restricted cash - Restricted Equity securities available-for-sale 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 September 30, 2017 December 31, 2016 Carrying Fair Value Carrying Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Long-term debt $ 12,850 $ 13,217 $ — $ 9,640 $ 3,577 $ 10,767 $ 11,055 $ — $ 8,184 $ 2,871 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.

Hedging Activities

Hedging Activities	9 Months Ended
	Sep. 30, 2017
Hedging Activities	NOTE 7 - HEDGING Fuel Derivatives As of September 30, 2017, the Company did not have any fuel hedging contracts outstanding to hedge its fuel consumption. The last of the Company’s fuel hedge derivatives designated for cash flow hedge accounting expired in December 2016. The Company’s current strategy is to not enter into transactions to hedge its fuel consumption, although the Company regularly reviews its strategy based on market conditions and other factors. The following table presents the impact of derivative instruments and their location within the Company’s unaudited statements of consolidated operations (in millions): Derivatives designated as cash flow hedges Amount of Loss Recognized in AOCI on Derivatives (Effective Portion) Loss Reclassified from Fuel Expense Three Months Ended Three Months Ended 2017 2016 2017 2016 Fuel contracts $ — $ (6) $ — $ (24) Amount of Loss Recognized in AOCI on Derivatives (Effective Portion) Loss Reclassified from Nine Months Ended Nine Months Ended 2017 2016 2017 2016 Fuel contracts $ — $ (5) $ (2) $ (197) (a) The 2017 loss reclassified from AOCI into fuel expense represents hedge losses on December 2016 settled trades, but for which the associated fuel purchased in December was not consumed until January 2017.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies	NOTE 8 - COMMITMENTS Commitments. Aircraft Type Number of Firm Airbus A350 45 Boeing 737 MAX 161 Boeing 777-300ER 4 Boeing 787 18 Embraer E175 5 (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 2017, United expects to take delivery of five Embraer E175 aircraft. Additionally, the Company also currently expects to take delivery of four used Airbus A319s and two used Airbus A320s for the remainder of 2017. The table below summarizes United’s commitments as of September 30, 2017, 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 three months of 2017 $ 0.9 2018 3.0 2019 3.1 2020 2.2 2021 1.4 After 2021 11.4 $ 22.0 United secured individual bank financing for five Embraer E175 aircraft to be delivered in the last three months of 2017. See Note 9 of this report for additional information on aircraft financing. The Company has also secured backstop financing commitments from certain of its aircraft manufacturers for a limited number of its future aircraft deliveries, subject to certain customary conditions. Financing may be necessary to satisfy the Company’s capital commitments for its firm order aircraft and other related capital expenditures. Regional CPAs. In the third quarter of 2017, United reached agreements with certain of its regional air partners to accelerate the retirement of 21 turboprop aircraft from service, modify some aircraft service entry and exit dates, as well as extend the term of up to approximately 125 aircraft under an existing CPA through December 31, 2022. The future commitments have been incorporated into the table below. The table below summarizes the Company’s future payments through the end of the terms of our CPAs, excluding variable pass-through costs such as fuel and landing fees, among others. (in billions) Last three months of 2017 $ 0.5 2018 2.0 2019 1.8 2020 1.6 2021 1.5 After 2021 4.6 $ 12.0 Guarantees. tax-exempt In the Company’s financing transactions that include loans, the Company 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 the London Interbank Offered Rate (“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 September 30, 2017, the Company had $3.3 billion of floating rate debt and $68 million of fixed rate debt, with remaining terms of up to 11 years, that are subject to these increased cost provisions. In several financing transactions involving loans or leases from non-U.S. non-U.S. As of September 30, 2017, United is the guarantor of $159 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	9 Months Ended
	Sep. 30, 2017
Debt	NOTE 9 - DEBT As of September 30, 2017, 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 September 30, 2017, UAL and United were in compliance with their debt covenants. 2017 Credit and Guaranty Agreement. take-off Borrowings under the 2017 Credit Agreement bear interest at a variable rate equal to LIBOR, subject to a 0% floor, plus a margin of 2.25% per annum, or another rate based on certain market interest rates, plus a margin of 1.25% 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, 2017, with any unpaid balance due on April 1, 2024. 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 2017 Credit Agreement includes covenants that, among other things, require the Company to maintain at least $2.0 billion of unrestricted liquidity and a minimum ratio of appraised value of collateral to the outstanding obligations under the Credit Agreement of 1.60 to 1.0. The 2017 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. Under the provisions of the 2017 Credit Agreement, UAL’s ability to make investments and to pay dividends on, or repurchase, UAL’s common stock is restricted. EETCs . EETC Date Class Principal Final expected Stated Total debt recorded 2017 Proceeds received from issuance of debt during September 2016 AA $ 637 October 2028 2.875% $ 637 $ 557 September 2016 A 283 October 2028 3.10% 283 247 June 2016 AA 729 July 2028 3.10% 729 319 June 2016 A 324 July 2028 3.45% 324 142 $ 1,973 $ 1,973 $ 1,265 Secured Notes Payable. 4.25% Senior Notes due 2022. 5% Senior Notes due 2024. The table below presents the Company’s contractual principal payments (not including debt discount or debt issuance costs) at September 30, 2017 under then-outstanding long-term debt agreements (in millions): Last three months of 2017 $ 184 2018 1,527 2019 1,115 2020 1,120 2021 1,107 After 2021 7,963 $ 13,016

Special Charges

Special Charges	9 Months Ended
	Sep. 30, 2017
Special Charges	NOTE 10 - SPECIAL CHARGES For the three and nine months ended September 30, special charges consisted of the following (in millions): Three Months Ended Nine Months Ended Operating: 2017 2016 2017 2016 Severance and benefit costs $ 23 $ 13 $ 101 $ 27 Impairment of assets 15 — 15 412 Labor agreement costs — 14 — 124 Cleveland airport lease restructuring — — — 74 (Gains) losses on sale of assets and other special charges 12 18 29 32 Special charges 50 45 145 669 Nonoperating: Other (gain) loss — — — (1) Special charges before income taxes 50 45 145 668 Income tax benefit related to special charges (18) (16) (52) (241) Total special charges, net of tax $ 32 $ 29 $ 93 $ 427 During the three and nine months ended September 30, 2017, the Company recorded $16 million ($10 million net of taxes) and $73 million ($47 million net of taxes), respectively, of severance and benefit costs related to a voluntary early-out During the three and nine months ended September 30, 2016, the Company recorded $13 million ($8 million net of taxes) and $27 million ($17 million net of taxes), respectively, of severance and benefit costs primarily related to a voluntary early-out During the three months ended September 30, 2017, the Company recorded a $15 million ($10 million net of taxes) intangible asset impairment charge related to a maintenance service agreement. In April 2016, the Federal Aviation Administration (“FAA”) announced that, effective October 30, 2016, it would designate Newark Liberty International Airport (“Newark”) as a Level 2 schedule-facilitated airport under the International Air Transport Association Worldwide Slot Guidelines. The designation was associated with an updated demand and capacity analysis of Newark by the FAA. In the second quarter of 2016, the Company determined that the FAA’s action impaired the entire value of its Newark slots because the slots are no longer the mechanism that governs take-off During the nine months ended September 30, 2016, the fleet service, passenger service, storekeeper and other employees represented by the International Association of Machinists and Aerospace Workers (the “IAM”) ratified seven new contracts with the Company which extended the contracts through 2021. The Company also reached a tentative agreement with the IBT during the same time period. During the three and nine months ended September 30, 2016, the Company recorded $61 million ($39 million net of taxes) and $171 million ($109 million net of taxes), respectively, of special charges primarily for payments in conjunction with the IAM and IBT agreements described above. Also, as part of its contract with the Association of Flight Attendants, the Company amended two of its flight attendant postretirement medical plans. The amendments triggered curtailment accounting, resulting in the recognition of a one-time During the nine months ended September 30, 2016, the City of Cleveland agreed to amend the Company’s lease, which runs through 2029, associated with certain excess airport terminal space (principally Terminal D) and related facilities at Hopkins International Airport. The Company recorded an accrual for remaining payments under the lease for facilities that the Company no longer uses and will continue to incur costs under the lease without economic benefit to the Company. This liability was measured and recorded at its fair value when the Company ceased its right to use such facilities leased to it pursuant to the lease. The Company recorded a special charge of $74 million ($47 million net of taxes) related to the amended lease. Accrual The accrual balance for severance and benefits was $31 million as of September 30, 2017, compared to $34 million as of September 30, 2016. The severance-related accrual as of September 30, 2017 is expected to be mostly paid through early 2019. The accrual balance for future lease payments on permanently grounded aircraft was $28 million as of September 30, 2017, compared to $41 million as of September 30, 2016. The grounded aircraft related accrual as of September 30, 2017 is expected to be mostly paid through 2025. The following is a reconciliation of severance and permanently grounded aircraft accrual activity for the nine months ended September 30: Severance and Permanently Grounded Balance at December 31, 2016 $ 14 $ 41 Accrual 101 — Payments (84) (13) Balance at September 30, 2017 $ 31 $ 28 Severance and Permanently Balance at December 31, 2015 $ 27 $ 78 Accrual 27 (17) Payments (20) (20) Balance at September 30, 2016 $ 34 $ 41

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
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 Nine Months Ended 2017 2016 2017 2016 Earnings available to common stockholders $ 637 $ 965 $ 1,551 $ 1,866 Basic weighted-average shares outstanding 299.8 320.0 306.8 334.9 Effect of employee stock awards 0.8 0.4 0.8 0.3 Diluted weighted-average shares outstanding 300.6 320.4 307.6 335.2 Earnings per share, basic $ 2.12 $ 3.02 $ 5.06 $ 5.57 Earnings per share, diluted $ 2.12 $ 3.01 $ 5.04 $ 5.57

Accumulated Other Comprehensi19

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2017
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), net of tax (“AOCI”) (in millions): Deferred Taxes UAL Pension and Fuel Investments Pension and Fuel Investments Total Balance at June 30, 2017 $ (860) $ — $ (16) $ 26 $ — $ 6 $ (844) Changes in value (9) — 26 3 — (9) 11 Amounts reclassified to earnings 14 — — (5) — — 9 Net change 5 — 26 (2) — (9) 20 Balance at September 30, 2017 $ (855) $ — $ 10 $ 24 $ — $ (3) $ (824) Balance at December 31, 2016 $ (854) $ (2) $ 1 $ 24 $ 1 $ 1 $ (829) Changes in value (42) — 9 15 — (3) (21) Amounts reclassified to earnings 41 2 — (15) (1) (1) 26 Net change (1) 2 9 — (1) (4) 5 Balance at September 30, 2017 $ (855) $ — $ 10 $ 24 $ — $ (3) $ (824) Deferred Taxes UAL Pension and Fuel Investments Pension and Fuel Investments Total Balance at June 30, 2016 $ (385) $ (41) $ 3 $ (146) $ (165) $ — $ (734) Changes in value (124) (6) 1 45 2 (1) (83) Amounts reclassified to earnings 6 24 (2) (2) (8) 1 19 Net change (118) 18 (1) 43 (6) — (64) Balance at September 30, 2016 $ (503) $ (23) $ 2 $ (103) $ (171) $ — $ (798) Balance at December 31, 2015 $ (363) $ (215) $ 3 $ (154) $ (102) $ — $ (831) Changes in value (157) (5) 1 57 2 (1) (103) Amounts reclassified to earnings 17 197 (2) (6) (71) 1 136 Net change (140) 192 (1) 51 (69) — 33 Balance at September 30, 2016 $ (503) $ (23) $ 2 $ (103) $ (171) $ — $ (798) Details about AOCI Components Amount Reclassified from AOCI to Income Affected Line Item in the Statements of Consolidated Operations Three Months Ended Nine Months Ended 2017 2016 2017 2016 Pension and other postretirement liabilities Amortization of unrecognized losses and prior service cost (a) $ 14 $ 6 $ 41 $ 17 Salaries and related costs Fuel derivative contracts Reclassifications of losses into earnings — 24 2 197 Aircraft fuel Investments and other Reclassifications of gains into earnings — (2) — (2) Miscellaneous, net (a) This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 5 of this report for additional information).

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Components of Net Periodic Benefit Cost	The Company’s net periodic benefit cost includes the following components (in millions): Pension Benefits Other Postretirement Three Months Ended September 30, Three Months Ended September 30, 2017 2016 2017 2016 Service cost $ 48 $ 29 $ 4 $ 4 Interest cost 55 50 16 22 Expected return on plan assets (61) (54) — — Amortization of unrecognized (gain) loss and prior service cost (credit) 32 19 (18) (13) Settlement loss 3 2 — — Curtailment gain — — — (47) Total $ 77 $ 46 $ 2 $ (34) Pension Benefits Other Postretirement Nine Months Ended Nine Months Ended 2017 2016 2017 2016 Service cost $ 146 $ 84 $ 10 $ 14 Interest cost 165 151 50 66 Expected return on plan assets (182) (162) (1) (1) Amortization of unrecognized (gain) loss and prior service cost (credit) 95 57 (54) (40) Settlement loss 5 4 — — Curtailment gain — — — (47) Total $ 229 $ 134 $ 5 $ (8)
Share-Based Compensation Expense	The table below presents information related to share-based compensation (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Share-based compensation expense $ 10 $ 23 $ 66 $ 36 September 30, December 31, Unrecognized share-based compensation $ 90 $ 65

Financial Instruments and Fai21

Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
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): September 30, 2017 December 31, 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 1,870 $ 1,870 $ — $ — $ 2,179 $ 2,179 $ — $ — Short-term investments: Corporate debt 959 — 959 — 835 — 835 — Asset-backed securities 891 — 891 — 792 — 792 — Certificates of deposit placed through an account registry service (“CDARS”) 142 — 142 — 246 — 246 — U.S. government and agency notes 112 — 112 — 140 — 140 — Other fixed-income securities 171 — 171 — 54 — 54 — Other investments measured at NAV 183 — — — 182 — — — Restricted cash 109 109 — — 124 124 — — Long-term investments: Equity securities 114 114 — — — — — — Enhanced equipment trust certificates (“EETC”) 21 — — 21 23 — — 23
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 September 30, 2017 December 31, 2016 Carrying Fair Value Carrying Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Long-term debt $ 12,850 $ 13,217 $ — $ 9,640 $ 3,577 $ 10,767 $ 11,055 $ — $ 8,184 $ 2,871

Hedging Activities (Tables)

Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2017
Schedule of Gain on Derivative Instruments	The following table presents the impact of derivative instruments and their location within the Company’s unaudited statements of consolidated operations (in millions): Derivatives designated as cash flow hedges Amount of Loss Recognized in AOCI on Derivatives (Effective Portion) Loss Reclassified from Fuel Expense Three Months Ended Three Months Ended 2017 2016 2017 2016 Fuel contracts $ — $ (6) $ — $ (24) Amount of Loss Recognized in AOCI on Derivatives (Effective Portion) Loss Reclassified from Nine Months Ended Nine Months Ended 2017 2016 2017 2016 Fuel contracts $ — $ (5) $ (2) $ (197) (a) The 2017 loss reclassified from AOCI into fuel expense represents hedge losses on December 2016 settled trades, but for which the associated fuel purchased in December was not consumed until January 2017.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Schedule of Commitments to Purchase Aircrafts	The table below summarizes United’s commitments as of September 30, 2017, 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 three months of 2017 $ 0.9 2018 3.0 2019 3.1 2020 2.2 2021 1.4 After 2021 11.4 $ 22.0
Future Lease Payment Under Terms of Capacity Purchase Agreement	The table below summarizes the Company’s future payments through the end of the terms of our CPAs, excluding variable pass-through costs such as fuel and landing fees, among others. (in billions) Last three months of 2017 $ 0.5 2018 2.0 2019 1.8 2020 1.6 2021 1.5 After 2021 4.6 $ 12.0
Aircraft Type
Schedule of Commitments to Purchase Aircrafts	As of September 30, 2017, United had firm commitments and options to purchase aircraft from The Boeing Company (“Boeing”), Airbus S.A.S. (“Airbus”), and Embraer S.A. (“Embraer”) presented in the table below: Aircraft Type Number of Firm Airbus A350 45 Boeing 737 MAX 161 Boeing 777-300ER 4 Boeing 787 18 Embraer E175 5 (a) United also has options and purchase rights for additional aircraft.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Details of Pass Through Trusts	Certain details of the pass-through trusts with proceeds received from issuance of debt in 2017 are as follows (in millions, except stated interest rate): EETC Date Class Principal Final expected Stated Total debt recorded 2017 Proceeds received from issuance of debt during September 2016 AA $ 637 October 2028 2.875% $ 637 $ 557 September 2016 A 283 October 2028 3.10% 283 247 June 2016 AA 729 July 2028 3.10% 729 319 June 2016 A 324 July 2028 3.45% 324 142 $ 1,973 $ 1,973 $ 1,265
Contractual Principal Payments	The table below presents the Company’s contractual principal payments (not including debt discount or debt issuance costs) at September 30, 2017 under then-outstanding long-term debt agreements (in millions): Last three months of 2017 $ 184 2018 1,527 2019 1,115 2020 1,120 2021 1,107 After 2021 7,963 $ 13,016

Special Charges (Tables)

Special Charges (Tables)	9 Months Ended
	Sep. 30, 2017
Components of Special Charges	For the three and nine months ended September 30, special charges consisted of the following (in millions): Three Months Ended Nine Months Ended Operating: 2017 2016 2017 2016 Severance and benefit costs $ 23 $ 13 $ 101 $ 27 Impairment of assets 15 — 15 412 Labor agreement costs — 14 — 124 Cleveland airport lease restructuring — — — 74 (Gains) losses on sale of assets and other special charges 12 18 29 32 Special charges 50 45 145 669 Nonoperating: Other (gain) loss — — — (1) Special charges before income taxes 50 45 145 668 Income tax benefit related to special charges (18) (16) (52) (241) Total special charges, net of tax $ 32 $ 29 $ 93 $ 427
Schedule of Severance Related Accrual	The following is a reconciliation of severance and permanently grounded aircraft accrual activity for the nine months ended September 30: Severance and Permanently Grounded Balance at December 31, 2016 $ 14 $ 41 Accrual 101 — Payments (84) (13) Balance at September 30, 2017 $ 31 $ 28 Severance and Permanently Balance at December 31, 2015 $ 27 $ 78 Accrual 27 (17) Payments (20) (20) Balance at September 30, 2016 $ 34 $ 41

Recently Issued Accounting St26

Recently Issued Accounting Standards - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification from other operating revenue into passenger revenue	$ 8,528	$ 8,603	$ 24,324	$ 23,696
Topic 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification from other operating revenue into passenger revenue					$ 2,000

Computation of Earnings Per Sha

Computation of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Computation of Earnings Per Share [Line Items]
Earnings available to common stockholders	$ 637	$ 965	$ 1,551	$ 1,866
Basic weighted-average shares outstanding	299.8	320	306.8	334.9
Effect of employee stock awards	0.8	0.4	0.8	0.3
Diluted weighted-average shares outstanding	300.6	320.4	307.6	335.2
Earnings per share, basic	$ 2.12	$ 3.02	$ 5.06	$ 5.57
Earnings per share, diluted	$ 2.12	$ 3.01	$ 5.04	$ 5.57

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) shares in Millions, $ in Billions	3 Months Ended	9 Months Ended
	Sep. 30, 2017USD ($)shares	Sep. 30, 2017USD ($)shares
Earnings Loss Per Share [Line Items]
Amount remaining under repurchase programs	$ 0.6	$ 0.6
Open Market Repurchase Program
Earnings Loss Per Share [Line Items]
Number of shares repurchased | shares	8	18
Repurchases of common stock	$ 0.6	$ 1.3

Components of Accumulated Other

Components of Accumulated Other Comprehensive Income (Loss), Net of Tax (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, net of tax		$ (734)	$ 8,659	$ (831)
Changes in value, net of tax		(83)		(103)
Amounts reclassified to earnings, net of tax		19		136
Total other comprehensive income (loss), net	$ 20	(64)	5	33
Ending Balance, net of tax	8,970	(798)	8,970	(798)
Pension and Other Postretirement Liabilities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, before tax	(860)	(385)	(854)	(363)
Changes in value, before tax	(9)	(124)	(42)	(157)
Amounts reclassified to earnings, before tax	14	6	41	17
Net change, before tax	5	(118)	(1)	(140)
Ending Balance, before tax	(855)	(503)	(855)	(503)
Beginning Balance, deferred taxes	26	(146)	24	(154)
Changes in value, deferred taxes	3	45	15	57
Amounts reclassified to earnings, deferred taxes	(5)	(2)	(15)	(6)
Net change, deferred taxes	(2)	43		51
Ending Balance, deferred taxes	24	(103)	24	(103)
Derivative Contracts | Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, before tax		(41)	(2)	(215)
Changes in value, before tax		(6)		(5)
Amounts reclassified to earnings, before tax		24	2	197
Net change, before tax		18	2	192
Ending Balance, before tax		(23)		(23)
Beginning Balance, deferred taxes		(165)	1	(102)
Changes in value, deferred taxes		2		2
Amounts reclassified to earnings, deferred taxes		(8)	(1)	(71)
Net change, deferred taxes		(6)	(1)	(69)
Ending Balance, deferred taxes		(171)		(171)
Investments and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, before tax	(16)	3	1	3
Changes in value, before tax	26	1	9	1
Amounts reclassified to earnings, before tax		(2)		(2)
Net change, before tax	26	(1)	9	(1)
Ending Balance, before tax	10	2	10	2
Beginning Balance, deferred taxes	6		1
Changes in value, deferred taxes	(9)	(1)	(3)	(1)
Amounts reclassified to earnings, deferred taxes		$ 1	(1)	$ 1
Net change, deferred taxes	(9)		(4)
Ending Balance, deferred taxes	(3)		(3)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, net of tax	(844)		(829)
Changes in value, net of tax	11		(21)
Amounts reclassified to earnings, net of tax	9		26
Total other comprehensive income (loss), net	20		5
Ending Balance, net of tax	$ (824)		$ (824)

Details about Accumulated Other

Details about Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Salaries And Related Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of unrecognized losses and prior service cost	[1]	$ 14	$ 6	$ 41	$ 17
Miscellaneous, Net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications of gains into earnings			(2)		(2)
Fuel Oil Contract | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications of losses into earnings			$ 24	$ 2	$ 197
[1]	This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 5 of this report for additional information).

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Line Items]
Effective income tax rate	35.00%	36.10%	35.30%	36.40%

Components of Net Periodic Bene

Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 48	$ 29	$ 146	$ 84
Interest cost	55	50	165	151
Expected return on plan assets	(61)	(54)	(182)	(162)
Amortization of unrecognized (gain) loss and prior service cost (credit)	32	19	95	57
Settlement loss	3	2	5	4
Total	77	46	229	134
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	10	14
Interest cost	16	22	50	66
Expected return on plan assets			(1)	(1)
Amortization of unrecognized (gain) loss and prior service cost (credit)	(18)	(13)	(54)	(40)
Curtailment gain		(47)		(47)
Total	$ 2	$ (34)	$ 5	$ (8)

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) shares in Thousands, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Pension Benefits
Compensation and Retirement Disclosure [Abstract]
Employer contribution to tax-qualified defined benefit pension plans	$ 160	$ 400
RSUs
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, other than options, awards granted		1,500
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, 2019
Number of days used to compute performance period average closing price of restricted stock units		20 days
Stock Options
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, option awards granted		36
Time Vested Restricted Stock Units RSU
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, other than options, awards granted		900
Performance Based Restricted Stock Units RSU
Compensation and Retirement Disclosure [Abstract]
Share-based compensation, other than options, awards granted		600

Share-Based Compensation Expens

Share-Based Compensation Expense (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share-based compensation expense	$ 10	$ 23	$ 66	$ 36
Unrecognized share-based compensation	$ 90		$ 90		$ 65

Financial Assets and Liabilitie

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 1,870	$ 2,179
Restricted cash	109	124
Equity securities	114
Enhanced equipment trust certificates ("EETC")	21	23
Corporate Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	959	835
Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	891	792
CDARS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	142	246
U.S. Government and Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	112	140
Other Fixed Income Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	171	54
Other Investments Measured At NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	183	182
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,870	2,179
Restricted cash	109	124
Equity securities	114
Level 2 | Corporate Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	959	835
Level 2 | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	891	792
Level 2 | CDARS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	142	246
Level 2 | U.S. Government and Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	112	140
Level 2 | Other Fixed Income Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	171	54
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Enhanced equipment trust certificates ("EETC")	$ 21	$ 23

Financial Instruments and Fai36

Financial Instruments and Fair Value Measurements - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017
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	2 years

Carrying Values and Estimated F

Carrying Values and Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Carrying (Reported) Amount, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 12,850	$ 10,767
Estimate of Fair Value, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt fair value	13,217	11,055
Estimate of Fair Value, Fair Value Disclosure | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt fair value	9,640	8,184
Estimate of Fair Value, Fair Value Disclosure | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt fair value	$ 3,577	$ 2,871

Hedging Activities - Additional

Hedging Activities - Additional Information (Detail) - Fuel Contract	9 Months Ended
	Sep. 30, 2017Contract
Derivatives And Hedging Activities [Line Items]
Fuel hedging contracts outstanding	0
Cash Flow Hedging | Designated as Hedging Instrument
Derivatives And Hedging Activities [Line Items]
Fuel hedges expiration date	2016-12

Schedule of Gain on Derivative

Schedule of Gain on Derivative Instruments (Detail) - Designated as Hedging Instrument - Cash Flow Hedging - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2017	[1]	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Loss Recognized in AOCI on Derivatives (Effective Portion)	$ (6)			$ (5)
Loss Reclassified from AOCI into Fuel Expense	$ (24)	$ (2)		$ (197)
[1]	The 2017 loss reclassified from AOCI into fuel expense represents hedge losses on December 2016 settled trades, but for which the associated fuel purchased in December was not consumed until January 2017.

Schedule of Commitments to Purc

Schedule of Commitments to Purchase Aircrafts (Detail) - United Airlines, Inc. - Capital Addition Purchase Commitments	Sep. 30, 2017Aircraft	[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	4
Boeing 787 Aircraft
Long-term Purchase Commitment [Line Items]
Number of new aircraft committed to purchase	18
Embraer E175 Aircraft
Long-term Purchase Commitment [Line Items]
Number of new aircraft committed to purchase	5
[1]	United also has options and purchase rights for additional aircraft.

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Feb. 17, 2017Aircraft	Sep. 30, 2017USD ($)EmployeeAircraft	Sep. 30, 2017USD ($)EmployeeAircraft
Commitments and Contingencies [Line Items]
Aggregate balance		$ 12,000,000,000	$ 12,000,000,000
Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure		1,800,000,000	1,800,000,000
Operating leases obligations		1,400,000,000	1,400,000,000
Capital leases obligations		441,000,000	441,000,000
Floating Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount		3,300,000,000	3,300,000,000
Fixed Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount		68,000,000	68,000,000
Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Aggregate balance		3,200,000,000	3,200,000,000
Aircraft Mortgage Debt
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure		$ 159,000,000	$ 159,000,000
Minimum | Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Debt instrument maturity year			2,019
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
Air Wisconsin | Maximum | CRJ 200
Commitments and Contingencies [Line Items]
Number of aircraft to operate | Aircraft	65
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of aircrafts under the extended term of contract | Aircraft		125
Capacity purchase agreement contract expiration date after extension		Dec. 31, 2022
Debt instrument maturity year			2,027
Debt instrument principal amount		$ 392,000,000	$ 392,000,000
Number of employees | Employee		89,700	89,700
Percentage of employees represented by various U.S. labor organizations			80.00%
United Airlines, Inc. | Turboprop Aircraft [Member]
Commitments and Contingencies [Line Items]
Number of aircraft to be retire from service | Aircraft		21	21
United Airlines, Inc. | Delivered in Last Three Months of 2017 | Embraer E175 Aircraft
Commitments and Contingencies [Line Items]
Number of additional aircraft ordered for future delivery | Aircraft		5	5
United Airlines, Inc. | Capital Addition Purchase Commitments
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date			2,027
United Airlines, Inc. | Capital Addition Purchase Commitments | Embraer E175 Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 | Aircraft		5	5
United Airlines, Inc. | Capital Addition Purchase Commitments | A319 aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 | Aircraft		4	4
United Airlines, Inc. | Capital Addition Purchase Commitments | Airbus A320 Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 | Aircraft		2	2

Schedule of Acquisition of Airc

Schedule of Acquisition of Aircrafts and Related Spare Engines (Detail) $ in Billions	Sep. 30, 2017USD ($)
Unrecorded Unconditional Purchase Obligation [Line Items]
Last three months of 2017	$ 0.9
2,018	3
2,019	3.1
2,020	2.2
2,021	1.4
After 2,021	11.4
Total commitments	$ 22

Future Lease Payment Under Term

Future Lease Payment Under Terms of Capacity Purchase Agreement (Detail) $ in Billions	Sep. 30, 2017USD ($)
Long-term Purchase Commitment [Line Items]
Last three months of 2017	$ 0.5
2,018	2
2,019	1.8
2,020	1.6
2,021	1.5
After 2,021	4.6
Contractual Obligation, Total	$ 12

Debt - Additional Information (

Debt - Additional Information (Detail)	1 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Jan. 30, 2017USD ($)	Sep. 30, 2017USD ($)
Credit Agreement
Debt Instrument [Line Items]
Minimum ratio of appraised value of collateral to the outstanding obligations	1.60		1.60
Credit Agreement | Minimum
Debt Instrument [Line Items]
Credit Agreement Covenants Minimum Liquidity Requirement Value			$ 2,000,000,000
United Airlines, Inc.
Debt Instrument [Line Items]
Aggregate principal amount	$ 392,000,000		$ 392,000,000
Debt instrument maturity year			2,027
United Airlines, Inc. | 4.25% Senior Notes due 2022
Debt Instrument [Line Items]
Aggregate principal amount	$ 400,000,000		$ 400,000,000
Debt instrument maturity date	Oct. 1, 2022
Debt instrument stated interest rate	4.25%		4.25%
Notes repurchase price	101.00%
United Airlines, Inc. | 5% Senior Notes due 2024
Debt Instrument [Line Items]
Aggregate principal amount		$ 300,000,000
Debt instrument maturity date		Feb. 1, 2024
Debt instrument stated interest rate		5.00%
Notes repurchase price		101.00%
United Airlines, Inc. | Revolving Credit Facility
Debt Instrument [Line Items]
Commitment fee percentage			0.75%
United Airlines, Inc. | Secured Debt
Debt Instrument [Line Items]
Quarterly principal repayment amount	0.25%		0.25%
United Airlines, Inc. | Secured Debt | Term Loan Due April 1, 2024 [Member] | Interest Rate Floor
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			0.00%
United Airlines, Inc. | Secured Debt | Term Loan Due April 1, 2024 [Member] | LIBOR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			2.25%
United Airlines, Inc. | Secured Debt | Term Loan Due April 1, 2024 [Member] | Certain Market Interest Rates
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.25%
United Airlines, Inc. | Secured Debt | Term Loan Facility Due April 1, 2024
Debt Instrument [Line Items]
Aggregate principal amount	$ 1,500,000,000		$ 1,500,000,000
Debt instrument maturity date			Apr. 1, 2024
Increase in term loan balance			$ 440,000,000
United Airlines, Inc. | Secured Debt | Revolving Credit Facility
Debt Instrument [Line Items]
Credit agreement	2,000,000,000		2,000,000,000
United Airlines, Inc. | Secured Debt | Revolving Credit Facility Available For Drawing Until April 1, 2022
Debt Instrument [Line Items]
Credit agreement	$ 2,000,000,000		$ 2,000,000,000
Revolving credit facility available for drawing date			Apr. 1, 2022

Details of Pass Through Trusts

Details of Pass Through Trusts (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Proceeds received from issuance of debt	$ 2,119	$ 510
United Airlines, Inc.
Debt Instrument [Line Items]
Principal	392
Proceeds received from issuance of debt	2,119	$ 510
United Airlines, Inc. | Class AA Pass Through Certificates | September 2016
Debt Instrument [Line Items]
Principal	$ 637
Final expected distribution date	2028-10
Stated interest rate	2.875%
Total debt recorded	$ 637
Proceeds received from issuance of debt	557
United Airlines, Inc. | Class AA Pass Through Certificates | June 2016
Debt Instrument [Line Items]
Principal	$ 729
Final expected distribution date	2028-07
Stated interest rate	3.10%
Total debt recorded	$ 729
Proceeds received from issuance of debt	319
United Airlines, Inc. | Class A Pass Through Certificates | September 2016
Debt Instrument [Line Items]
Principal	$ 283
Final expected distribution date	2028-10
Stated interest rate	3.10%
Total debt recorded	$ 283
Proceeds received from issuance of debt	247
United Airlines, Inc. | Class A Pass Through Certificates | June 2016
Debt Instrument [Line Items]
Principal	$ 324
Final expected distribution date	2028-07
Stated interest rate	3.45%
Total debt recorded	$ 324
Proceeds received from issuance of debt	142
United Airlines, Inc. | EETC
Debt Instrument [Line Items]
Principal	1,973
Total debt recorded	1,973
Proceeds received from issuance of debt	$ 1,265

Contractual Principal Payments

Contractual Principal Payments Not Including Debt Discount Or Debt Issuance Costs (Detail) - UAL and United $ in Millions	Sep. 30, 2017USD ($)
Debt Instrument [Line Items]
Last three months of 2017	$ 184
2,018	1,527
2,019	1,115
2,020	1,120
2,021	1,107
After 2,021	7,963
Long-term debt	$ 13,016

Components of Special Charges (

Components of Special Charges (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating:
Severance and benefit costs	$ 23	$ 13	$ 101	$ 27
Impairment of assets	15		15	412
Labor agreement costs		14		124
Cleveland airport lease restructuring				74
(Gains) losses on sale of assets and other special charges	12	18	29	32
Special charges	50	45	145	669
Nonoperating:
Other (gain) loss				(1)
Special charges before income taxes	50	45	145	668
Income tax benefit related to special charges	(18)	(16)	(52)	(241)
Total special charges, net of tax	$ 32	$ 29	$ 93	$ 427

Special Charges - Additional In

Special Charges - Additional Information (Detail)	3 Months Ended				9 Months Ended
	Sep. 30, 2017USD ($)	Mar. 31, 2017USD ($)Technician	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)plan
Special Charges [Line Items]
Severance and benefits costs	$ 23,000,000		$ 13,000,000		$ 101,000,000	$ 27,000,000
Severance and benefits costs net of tax			8,000,000			17,000,000
Impairment of assets	15,000,000				15,000,000	412,000,000
Labor agreement costs			14,000,000			$ 124,000,000
Lease maturity year						2,029
Cleveland airport lease restructuring						$ 74,000,000
Cleveland airport lease restructuring, net of taxes						47,000,000
Accrual severance and benefit	31,000,000		34,000,000		$ 31,000,000	34,000,000
Severance-related accrual expected payment date					2,019
Accrual for permanently grounded aircraft	28,000,000		41,000,000		$ 28,000,000	41,000,000
Grounded aircraft related accrual expected payment date					2,025
Postretirement Medical Plan | Flight Attendant Postretirement Medical Plan
Special Charges [Line Items]
Curtailment gain recognition of prior service credit						47,000,000
Curtailment gain recognition of prior service credit,net of tax						$ 30,000,000
Number of plans amended | plan						2
Newark Liberty International Airport
Special Charges [Line Items]
Impairment of indefinite-lived intangible assets				$ 412,000,000
Impairment of indefinite-lived intangible assets, net of tax benefits				$ 264,000,000
International Brotherhood of Teamsters
Special Charges [Line Items]
Severance and benefits costs	16,000,000				$ 73,000,000
Severance and benefits costs net of tax	10,000,000				47,000,000
Int'l Association of Machinists
Special Charges [Line Items]
Labor agreement costs			61,000,000			$ 171,000,000
Labor agreement costs net of tax			$ 39,000,000			$ 109,000,000
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	7,000,000				28,000,000
Severance and benefits costs net of tax	5,000,000				$ 18,000,000
Maintenance Service Agreement
Special Charges [Line Items]
Impairment of assets	15,000,000
Impairment of assets net of tax	$ 10,000,000

Schedule of Severance Related A

Schedule of Severance Related Accrual (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Severance and Benefits Costs
Schedule Of Accrual Activity [Line Items]
Beginning Balance	$ 14	$ 27
Accrual	101	27
Payments	(84)	(20)
Ending Balance	31	34
Permanently Grounded Aircraft
Schedule Of Accrual Activity [Line Items]
Beginning Balance	41	78
Accrual		(17)
Payments	(13)	(20)
Ending Balance	$ 28	$ 41