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Statements of Consolidated Cash Flows - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Operating Activities: |  |  |  |  |  |
Net income |  | $ 2,129 | $ 2,144 | [1],[2],[3],[4] | $ 2,234 | [1],[2],[3],[4]
Adjustments to reconcile net income to net cash provided by operating activities - |  |  |  |  |  |
Deferred income taxes |  | 515 | 973 | [3] | 1,631 | [3]
Depreciation and amortization |  | 2,240 | 2,149 | [1],[3] | 1,977 | [1],[3]
Special charges, non-cash portion |  | 416 | 35 | [3] | 391 | [3]
Other operating activities |  | 170 | 141 | [3] | 109 | [3]
Changes in operating assets and liabilities - |  |  |  |  |  |
Increase in receivables |  | (29) | (183) | [3] | (16) | [3]
(Increase) decrease in other assets |  | 29 | (533) | [3] | (296) | [3]
Increase (decrease) in advance ticket sales |  | 441 | 145 | [3] | (28) | [3]
Increase (decrease) in frequent flyer deferred revenue |  | 222 | (107) | [3] | (55) | [3]
Increase in accounts payable |  | 130 | 66 | [3] | 239 | [3]
Decrease in advanced purchase of miles |  | 0 | (942) | [3] | (206) | [3]
Decrease in other liabilities |  | (82) | (475) | [3] | (438) | [3]
Net cash provided by operating activities |  | 6,181 | 3,413 | [3] | 5,542 | [3]
Investing Activities: |  |  |  |  |  |
Capital expenditures |  | (4,177) | (3,998) | [3] | (3,223) | [3]
Purchases of short-term and other investments |  | (2,552) | (3,241) | [3] | (2,768) | [3]
Proceeds from sale of short-term and other investments |  | 2,616 | 3,177 | [3] | 2,712 | [3]
Loans made to others |  | (466) | (30) | [3] | (56) | [3]
Investment in affiliates |  | (139) | (2) | [3] | (14) | [3]
Other, net |  | 155 | 164 | [3] | 111 | [3]
Net cash used in investing activities |  | (4,563) | (3,930) | [3] | (3,238) | [3]
Financing Activities: |  |  |  |  |  |
Proceeds from issuance of long-term debt and airport construction financing |  | 1,740 | 2,765 | [3] | 808 | [3]
Payments of long-term debt |  | (1,727) | (901) | [3] | (1,215) | [3]
Repurchases of common stock |  | (1,235) | (1,844) | [3] | (2,614) | [3]
Principal payments under capital leases |  | (134) | (124) | [3] | (136) | [3]
Capitalized financing costs |  | (37) | (80) | [3] | (64) | [3]
Other, net |  | (17) | (11) | [3] | 8 | [3]
Net cash used in financing activities |  | (1,410) | (195) | [3] | (3,213) | [3]
Net increase (decrease) in cash, cash equivalents and restricted cash |  | 208 | (712) | [3] | (909) | [3]
Cash, cash equivalents and restricted cash at beginning of year | [3] | 1,591 | 2,303 |  | 3,212 |
Cash, cash equivalents and restricted cash at end of year |  | 1,799 | 1,591 | [3] | 2,303 | [3]
Investing and Financing Activities Not Affecting Cash: |  |  |  |  |  |
Property and equipment acquired through the issuance of debt and capital leases |  | 174 | 935 | [3] | 386 | [3]
Debt associated with termination of a maintenance service agreement |  | 163 | 0 | [3] | 0 | [3]
Investment in Republic Airways Holdings, Inc. received from bankruptcy claims |  | 0 | 92 | [3] | 0 | [3]
Airport construction financing |  | 12 | 42 | [3] | 91 | [3]
Operating lease conversions to capital lease |  | 52 | 0 | [3] | 12 | [3]
Cash Paid During the Period for: |  |  |  |  |  |
Interest |  | 651 | 571 | [3] | 584 | [3]
Income taxes |  | 19 | 20 | [3] | 14 | [3]
United Airlines, Inc. |  |  |  |  |  |
Operating Activities: |  |  |  |  |  |
Net income |  | 2,131 | 2,163 | [5],[6],[7] | 2,234 | [5],[6],[7]
Adjustments to reconcile net income to net cash provided by operating activities - |  |  |  |  |  |
Deferred income taxes |  | 515 | 956 | [6] | 1,633 | [6]
Depreciation and amortization |  | 2,240 | 2,149 | [6],[8] | 1,977 | [6],[8]
Special charges, non-cash portion |  | 416 | 35 | [6] | 391 | [6]
Other operating activities |  | 170 | 140 | [6] | 109 | [6]
Changes in operating assets and liabilities - |  |  |  |  |  |
Increase in receivables |  | (29) | (183) | [6] | (16) | [6]
Increase in intercompany receivables |  | (20) | (15) | [6] | (57) | [6]
(Increase) decrease in other assets |  | 29 | (533) | [6] | (250) | [6]
Increase (decrease) in advance ticket sales |  | 441 | 145 | [6] | (28) | [6]
Increase (decrease) in frequent flyer deferred revenue |  | 222 | (107) | [6] | (55) | [6]
Increase in accounts payable |  | 130 | 66 | [6] | 239 | [6]
Decrease in advanced purchase of miles |  | 0 | (942) | [6] | (206) | [6]
Decrease in other liabilities |  | (82) | (475) | [6] | (436) | [6]
Net cash provided by operating activities |  | 6,163 | 3,399 | [6] | 5,535 | [6]
Investing Activities: |  |  |  |  |  |
Capital expenditures |  | (4,177) | (3,998) | [6] | (3,223) | [6]
Proceeds from sale of short-term and other investments |  | (2,552) | (3,241) | [6] | (2,768) | [6]
Proceeds from sale of short-term and other investments |  | 2,616 | 3,177 | [6] | 2,712 | [6]
Loans made to others |  | (466) | (30) | [6] | (56) | [6]
Investment in affiliates |  | (139) | (2) | [6] | (14) | [6]
Other, net |  | 155 | 164 | [6] | 111 | [6]
Net cash used in investing activities |  | (4,563) | (3,930) | [6] | (3,238) | [6]
Financing Activities: |  |  |  |  |  |
Proceeds from issuance of long-term debt and airport construction financing |  | 1,740 | 2,765 | [6] | 808 | [6]
Payments of long-term debt |  | (1,727) | (901) | [6] | (1,215) | [6]
Dividend to UAL |  | (1,235) | (1,844) | [6] | (2,614) | [6]
Principal payments under capital leases |  | (134) | (124) | [6] | (136) | [6]
Capitalized financing costs |  | (37) | (80) | [6] | (64) | [6]
Other, net |  | 1 | 3 | [6] | 15 | [6]
Net cash used in financing activities |  | (1,392) | (181) | [6] | (3,206) | [6]
Net increase (decrease) in cash, cash equivalents and restricted cash |  | 208 | (712) | [6] | (909) | [6]
Cash, cash equivalents and restricted cash at beginning of year | [6] | 1,585 | 2,297 |  | 3,206 |
Cash, cash equivalents and restricted cash at end of year |  | 1,793 | 1,585 | [6] | 2,297 | [6]
Investing and Financing Activities Not Affecting Cash: |  |  |  |  |  |
Property and equipment acquired through the issuance of debt and capital leases |  | 174 | 935 | [6] | 386 | [6]
Debt associated with termination of a maintenance service agreement |  | 163 | 0 | [6] | 0 | [6]
Investment in Republic Airways Holdings, Inc. received from bankruptcy claims |  | 0 | 92 | [6] | 0 | [6]
Airport construction financing |  | 12 | 42 | [6] | 91 | [6]
Operating lease conversions to capital lease |  | 52 | 0 | [6] | 12 | [6]
Cash Paid During the Period for: |  |  |  |  |  |
Interest |  | 651 | 571 | [6] | 584 | [6]
Income taxes |  | $ 19 | $ 20 | [6] | $ 14 | [6]
[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 II, Item 8 of this report for additional information.
[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 II, Item 8 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). See Note 1 to the financial statements contained in Part II, Item 8 of this report for additional information.
[4] | 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 II, Item 8 of this report for additional information.
[5] | 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 II, Item 8 of this report for additional information.
[6] | 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 II, Item 8 of this report for additional information.
[7] | 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 II, Item 8 of this report for additional information.
[8] | 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 II, Item 8 of this report for additional information.

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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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- Definition The amount of fixed assets that an Entity acquires in a noncash (or part noncash) acquisition. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586 + Details
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- Definition Other cash or noncash adjustments to reconcile net income to cash provided by (used in) operating activities that are not separately disclosed in the statement of cash flows (for example, cash received or cash paid during the current period for miscellaneous operating activities, net change during the reporting period in other assets or other liabilities). + References No definition available. + Details
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- Definition The net cash paid (received) associated with the acquisition or disposal of all investments, including securities and other assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 + Details
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- Definition Amount of cash (inflow) outflow from investing activities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 + Details
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- Definition The cash outflow to reacquire common stock during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
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- Definition The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
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- Definition The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
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- Definition The cash outflow associated with the purchase of all investments (debt, security, other) during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
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- Definition The cash outflow for the purchase of loan receivable arising from the financing of goods and services. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
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- Definition The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
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- Definition The cash outflow for securities or other assets acquired, which qualify for treatment as an investing activity and are to be liquidated, if necessary, within the current operating cycle. Includes cash flows from securities classified as trading securities that were acquired for reasons other than sale in the short-term. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
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- Definition The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
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- Definition Amount of cash inflow (outflow) from financing activities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 + Details
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- Definition The cash outflow for the obligation for a lease meeting the criteria for capitalization (with maturities exceeding one year or beyond the operating cycle of the entity, if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
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- Definition The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
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- Definition Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan and expenses resulting from the write-down of assets. Excludes expenses related to a business combination, a discontinued operation or an asset retirement obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
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