This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479405/805-10-25-23

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The Proposed Merger with Spirit Airlines, Inc. ("Spirit") (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Transaction and merger-related costs	$ 0	$ 1	$ 10
Spirit Airlines, Inc Merger
Business Acquisition [Line Items]
Transaction and merger-related costs			(25)
Legal, Accounting and Other Fees \| Spirit Airlines, Inc.
Business Acquisition [Line Items]
Transaction and merger-related costs			16
Retention Bonus \| Spirit Airlines, Inc Merger
Business Acquisition [Line Items]
Transaction and merger-related costs			$ 19