Employee Benefit Plans - Schedule of Fair Value of Pension Plan Assets by Asset Category (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 11,395	$ 10,017	$ 9,707
Pension Benefits [Member] | Private Equity Partnerships [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	21	16
Pension Benefits [Member] | Insurance Group Annuity Contracts [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2	2
Pension Benefits [Member] | Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,395	10,017
Pension Benefits [Member] | Recurring [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,281	6,508
Pension Benefits [Member] | Recurring [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,936	2,556
Pension Benefits [Member] | Recurring [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	23
Pension Benefits [Member] | Recurring [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28	573
Pension Benefits [Member] | Recurring [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28	573
Pension Benefits [Member] | Recurring [Member] | International Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837	3,232
Pension Benefits [Member] | Recurring [Member] | International Markets [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837	3,232
Pension Benefits [Member] | Recurring [Member] | Large-Cap Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,451	2,253
Pension Benefits [Member] | Recurring [Member] | Large-Cap Companies [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,451	2,253
Pension Benefits [Member] | Recurring [Member] | Mid-Cap Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	744	371
Pension Benefits [Member] | Recurring [Member] | Mid-Cap Companies [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	744	371
Pension Benefits [Member] | Recurring [Member] | Small-Cap Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	125	6
Pension Benefits [Member] | Recurring [Member] | Small-Cap Companies [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	125	6
Pension Benefits [Member] | Recurring [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	55	49
Pension Benefits [Member] | Recurring [Member] | Mutual Funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	55	49
Pension Benefits [Member] | Recurring [Member] | Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,344	2,337
Pension Benefits [Member] | Recurring [Member] | Corporate Bonds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,344	2,337
Pension Benefits [Member] | Recurring [Member] | Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	238	150
Pension Benefits [Member] | Recurring [Member] | Government Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	238	150
Pension Benefits [Member] | Recurring [Member] | U.S. Municipal Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39	37
Pension Benefits [Member] | Recurring [Member] | U.S. Municipal Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39	37
Pension Benefits [Member] | Recurring [Member] | Private Equity Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	21
Pension Benefits [Member] | Recurring [Member] | Private Equity Partnerships [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	21
Pension Benefits [Member] | Recurring [Member] | Private Equity Partnerships Measured At Net Asset Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	879	703
Pension Benefits [Member] | Recurring [Member] | Common Collective Trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	315	32
Pension Benefits [Member] | Recurring [Member] | Common Collective Trusts [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	315	32
Pension Benefits [Member] | Recurring [Member] | Common Collective Trusts and 103-12 Investment Trust Measured at Net Asset Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	283	227
Pension Benefits [Member] | Recurring [Member] | Insurance Group Annuity Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
Pension Benefits [Member] | Recurring [Member] | Insurance Group Annuity Contracts [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
Pension Benefits [Member] | Recurring [Member] | Dividend and Interest Receivable [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44	40
Pension Benefits [Member] | Recurring [Member] | Dividend and Interest Receivable [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44	40
Pension Benefits [Member] | Recurring [Member] | Due to/from Brokers for Sale of Securities - Net [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	(9)
Pension Benefits [Member] | Recurring [Member] | Due to/from Brokers for Sale of Securities - Net [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	(9)
Pension Benefits [Member] | Recurring [Member] | Other Liabilities - Net [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(6)	(7)
Pension Benefits [Member] | Recurring [Member] | Other Liabilities - Net [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(6)	(7)
American Airlines, Inc. [Member] | Private Equity Partnerships [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	21	16
American Airlines, Inc. [Member] | Insurance Group Annuity Contracts [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2	2
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,340	9,968	$ 9,660
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,340	9,968
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,226	6,459
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,936	2,556
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	23
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28	573
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28	573
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | International Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837	3,232
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | International Markets [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837	3,232
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Large-Cap Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,451	2,253
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Large-Cap Companies [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,451	2,253
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Mid-Cap Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	744	371
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Mid-Cap Companies [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	744	371
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Small-Cap Companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	125	6
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Small-Cap Companies [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	125	6
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,344	2,337
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Corporate Bonds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,344	2,337
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	238	150
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Government Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	238	150
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | U.S. Municipal Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39	37
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | U.S. Municipal Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39	37
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Private Equity Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	21
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Private Equity Partnerships [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	21
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Private Equity Partnerships Measured At Net Asset Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	879	703
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Common Collective Trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	315	32
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Common Collective Trusts [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	315	32
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Common Collective Trusts and 103-12 Investment Trust Measured at Net Asset Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	283	227
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Insurance Group Annuity Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Insurance Group Annuity Contracts [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Dividend and Interest Receivable [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44	40
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Dividend and Interest Receivable [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44	40
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Due to/from Brokers for Sale of Securities - Net [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	(9)
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Due to/from Brokers for Sale of Securities - Net [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	(9)
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Other Liabilities - Net [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(6)	(7)
American Airlines, Inc. [Member] | Pension Benefits [Member] | Recurring [Member] | Other Liabilities - Net [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ (6)	$ (7)