Legal Proceedings (Details) shares in Millions, $ in Millions		1 Months Ended
	Jun. 15, 2018 USD ($)	Jun. 30, 2015 lawsuit	Sep. 30, 2018 shares
Long-term Purchase Commitment [Line Items]
Shares reserved for future issuance (in shares) | shares			24.5
Number of putative class action lawsuits | lawsuit		100
Preliminary settlement amount | $	$ 45
American Airlines, Inc. [Member]
Long-term Purchase Commitment [Line Items]
Number of putative class action lawsuits | lawsuit		100
Preliminary settlement amount | $	$ 45