Special Items - Additional Disclosures (Detail) - $ / Employees |
3 Months Ended | 12 Months Ended |
---|---|---|
Dec. 31, 2017 |
Dec. 31, 2017 |
|
Restructuring Cost and Reserve [Line Items] | ||
Tax reform bonus, amount per employee | 1,000 | |
Mainline [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Tax reform bonus, amount per employee | 1,000 | |
American Airlines, Inc. [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Tax reform bonus, amount per employee | 1,000 | |
American Airlines, Inc. [Member] | Mainline [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Tax reform bonus, amount per employee | 1,000 |