Commitments and Contingengies - Long-term Purchase Commitments (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($) aircraft
Aircraft
Long-term Purchase Commitment [Line Items]
Committed expenditures, 2019 \| $	$ 924
Committed expenditures, 2020 \| $	1,379
Committed expenditures, 2021 \| $	1,663
Committed expenditures, 2022 \| $	1,202
Committed expenditures, 2023 \| $	1,596
Committed expenditures, 2024 and beyond \| $	$ 3,444
B-737-8 Max
Long-term Purchase Commitment [Line Items]
Property, Plant and Equipment, Number of Aircraft Purchased \| aircraft	18
B-737-800
Long-term Purchase Commitment [Line Items]
Property, Plant and Equipment, Number of Aircraft Purchased \| aircraft	26
B-737-700
Long-term Purchase Commitment [Line Items]
Property, Plant and Equipment, Number of Aircraft Purchased \| aircraft	1
B-737-8 Max
Long-term Purchase Commitment [Line Items]
Long-term Purchase Commitment, Minimum Quantity Required \| aircraft	219
Options - 737MAX (in units) \| aircraft	115
B-737-7 Max
Long-term Purchase Commitment [Line Items]
Options - 737MAX (in units) \| aircraft	30

The amount the company has an option to purchase within the contractual purchase commitment.

No definition available.

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- Definition

Property, Plant and Equipment, Number of Aircraft Purchased

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.

+ References

No definition available.

+ Details

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77896938&loc=d3e25336-109308

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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