Represents the amount of aircrafts to be acquired under memorandums of understanding or non-binding commitments.

No definition available.

Name:	al_AircraftToBeAcquiredUnderNonBindingCommitment
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredAbstract
Namespace Prefix:	al_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the 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 after the fifth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredAfterFifthYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the 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 in the fifth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInFifthYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the 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 in the fourth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInFourthYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

+ References

No definition available.

+ Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInRemainderOfFiscalYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the 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 in the second fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInSecondYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the 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 in the third fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInThirdYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of long-range variants.

+ References

No definition available.

+ Details

Name:	al_NumberOfLongRangeVariants
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum amount of purchase arrangement maturing in the remainder of fiscal year.

+ References

No definition available.

+ Details

Name:	al_PurchaseObligationDueInRemainderOfFiscalYear
Namespace Prefix:	al_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount, at the balance sheet date, of deposits made to the manufacturer for new flight equipment still under construction. May include capitalized interest.

+ References

No definition available.

+ Details

Name:	us-gaap_DepositsOnFlightEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

Name:	us-gaap_LongTermPurchaseCommitmentMinimumQuantityRequired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount of purchase arrangement maturing after the fifth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligationDueAfterFifthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount of purchase arrangement maturing in the fifth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligationDueInFifthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount of purchase arrangement maturing in the fourth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligationDueInFourthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount of purchase arrangement maturing in the second fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligationDueInSecondYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount of purchase arrangement maturing in the third fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_PurchaseObligationDueInThirdYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_PurchaseObligationFiscalYearMaturityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_A330800900neoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_A330neoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA320321200Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA320321NEOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA321neoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA3501000Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA3509001000Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AircraftsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_ATR72600Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_B777300ERMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_B787910Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_Boeing73789MAXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_B737800Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	1 Months Ended
	Mar. 31, 2015 item	Mar. 31, 2015 item	Dec. 31, 2014
Commitments to acquire aircraft
2015	30
2016	33
2017	27
2018	39
2019	59
Thereafter	223
Total	411
Commitments for the acquisition of the aircraft and other equipment
2015	$ 1,794,679	1,794,679
2016	2,371,933	2,371,933
2017	1,976,016	1,976,016
2018	3,623,102	3,623,102
2019	4,737,097	4,737,097
Thereafter	18,420,914	18,420,914
Total	32,923,741us-gaap_PurchaseObligation	32,923,741us-gaap_PurchaseObligation
Deposits on flight equipment purchases	$ 1,147,637us-gaap_DepositsOnFlightEquipment	1,147,637us-gaap_DepositsOnFlightEquipment	$ 1,144,603us-gaap_DepositsOnFlightEquipment
Aircrafts \| Airbus
Commitments to acquire aircraft
Total		57
Airbus A320/321-200
Commitments to acquire aircraft
2015	6
2016	1
Total	7
Airbus A320/321neo
Commitments to acquire aircraft
2016	3
2017	12
2018	17
2019	27
Thereafter	81
Total	140
Number of long-range variants	30
Airbus A321neo LR \| Airbus
Commitments to acquire aircraft
Total		30
Airbus A330-800/900neo
Commitments to acquire aircraft
2018	5
2019	5
Thereafter	15
Total	25
Airbus A350-900/1000
Commitments to acquire aircraft
2018	2
2019	2
Thereafter	22
Total	26
Airbus A350-1000 \| Maximum
Commitments for the acquisition of the aircraft and other equipment
Aircraft to be acquired under non-binding commitment	5
Boeing 737-800
Commitments to acquire aircraft
2015	17
2016	15
2017	11
Total	43
Boeing 737-8/9 MAX
Commitments to acquire aircraft
2018	8
2019	18
Thereafter	78
Total	104
Boeing 777-300ER
Commitments to acquire aircraft
2015	6
2016	6
2017	2
Total	14
Boeing 787-9/10
Commitments to acquire aircraft
2016	3
2017	1
2018	7
2019	7
Thereafter	27
Total	45
ATR 42/72-600
Commitments to acquire aircraft
2015	1
2016	5
2017	1
Total	7
A330neo \| Airbus
Commitments to acquire aircraft
Total		25