Concentration of Risk (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) aircraft country customer lease	Dec. 31, 2015 USD ($) aircraft country customer lease	Dec. 31, 2014 USD ($)
Concentration of risk
Number of aircraft leased \| lease	85	90
Number of countries \| country	51	50
Minimum percentage of aircraft operated internationally based on net book value	95.00%
Number of aircraft sold or agreed to be sold \| aircraft	6	19
Net Book Value	$ 12,041,925	$ 10,813,475
Amount of Rental Revenue	$ 1,339,002	$ 1,174,544	$ 991,241
Geographic Region \| U.S. and Canada
Concentration of risk
Number of Customers \| customer	12	11
Percent of Total	14.10%	12.20%
Net book value of aircraft portfolio \| Geographic Region
Concentration of risk
Net Book Value	$ 12,041,925	$ 10,813,475
Percent of Total	100.00%	100.00%
Net book value of aircraft portfolio \| Geographic Region \| Europe
Concentration of risk
Net Book Value	$ 3,547,294	$ 3,238,323
Percent of Total	29.50%	30.00%
Net book value of aircraft portfolio \| Geographic Region \| China
Concentration of risk
Net Book Value	$ 2,779,546	$ 2,444,370
Percent of Total	23.00%	22.60%
Net book value of aircraft portfolio \| Geographic Region \| Asia (excluding China)
Concentration of risk
Net Book Value	$ 2,739,554	$ 2,313,477
Percent of Total	22.70%	21.40%
Net book value of aircraft portfolio \| Geographic Region \| Central America, South America And Mexico
Concentration of risk
Net Book Value	$ 937,287	$ 923,352
Percent of Total	7.80%	8.50%
Net book value of aircraft portfolio \| Geographic Region \| The Middle East And Africa
Concentration of risk
Net Book Value	$ 935,968	$ 1,023,715
Percent of Total	7.80%	9.50%
Net book value of aircraft portfolio \| Geographic Region \| U.S. and Canada
Concentration of risk
Net Book Value	$ 647,743	$ 446,839
Percent of Total	5.40%	4.10%
Net book value of aircraft portfolio \| Geographic Region \| Pacific, Australia, New Zealand
Concentration of risk
Net Book Value	$ 454,533	$ 423,399
Percent of Total	3.80%	3.90%
Number of customers \| Geographic Region
Concentration of risk
Number of Customers \| customer	85	90
Percent of Total	100.00%	100.00%
Number of customers \| Geographic Region \| Europe
Concentration of risk
Number of Customers \| customer	27	27
Percent of Total	31.80%	30.00%
Number of customers \| Geographic Region \| China
Concentration of risk
Number of Customers \| customer	9	12
Percent of Total	10.60%	13.40%
Number of customers \| Geographic Region \| Asia (excluding China)
Concentration of risk
Number of Customers \| customer	18	19
Percent of Total	21.20%	21.10%
Number of customers \| Geographic Region \| Central America, South America And Mexico
Concentration of risk
Number of Customers \| customer	9	11
Percent of Total	10.60%	12.20%
Number of customers \| Geographic Region \| The Middle East And Africa
Concentration of risk
Number of Customers \| customer	7	8
Percent of Total	8.20%	8.90%
Number of customers \| Geographic Region \| Pacific, Australia, New Zealand
Concentration of risk
Number of Customers \| customer	3	2
Percent of Total	3.50%	2.20%
Flight equipment revenue \| Geographic Region
Concentration of risk
Amount of Rental Revenue	$ 1,339,002	$ 1,174,544	$ 991,241
Percent of Total	100.00%	100.00%	100.00%
Flight equipment revenue \| Geographic Region \| Europe
Concentration of risk
Amount of Rental Revenue	$ 400,491	$ 380,295	$ 337,349
Percent of Total	29.90%	32.40%	34.00%
Flight equipment revenue \| Geographic Region \| China
Concentration of risk
Amount of Rental Revenue	$ 293,206	$ 265,450	$ 218,625
Percent of Total	21.90%	22.60%	22.10%
Flight equipment revenue \| Geographic Region \| Asia (excluding China)
Concentration of risk
Amount of Rental Revenue	$ 308,658	$ 223,284	$ 190,389
Percent of Total	23.10%	19.00%	19.20%
Flight equipment revenue \| Geographic Region \| Central America, South America And Mexico
Concentration of risk
Amount of Rental Revenue	$ 112,068	$ 114,672	$ 111,583
Percent of Total	8.40%	9.80%	11.30%
Flight equipment revenue \| Geographic Region \| The Middle East And Africa
Concentration of risk
Amount of Rental Revenue	$ 106,300	$ 90,416	$ 47,958
Percent of Total	7.90%	7.70%	4.90%
Flight equipment revenue \| Geographic Region \| U.S. and Canada
Concentration of risk
Amount of Rental Revenue	$ 69,918	$ 54,294	$ 55,007
Percent of Total	5.20%	4.60%	5.40%
Flight equipment revenue \| Geographic Region \| Pacific, Australia, New Zealand
Concentration of risk
Amount of Rental Revenue	$ 48,361	$ 46,133	$ 30,330
Percent of Total	3.60%	3.90%	3.10%

Represents the minimum percentage of aircraft operated internationally.

No definition available.

Name:	al_MinimumPercentageOfAircraftOperatedInternationally
Namespace Prefix:	al_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of aircraft leased.

+ References

No definition available.

+ Details

Name:	al_NumberOfAircraftLeased
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of customers of the entity.

+ References

No definition available.

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of countries in which the entity operates as of balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfCountriesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of revenue recognized for the period from operating leases, including minimum lease revenue, contingent revenue, percentage revenue and sublease revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=7501430&loc=d3e39896-112707

+ Details

Name:	us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of aircraft sold by the entity during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentNumberOfAircraftSold
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of property, by major property class, net of accumulated depreciation, subject to or available for lease as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718

+ Details

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

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_GeographicConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=al_UnitedStatesOfAmericaAndCanadaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_NetAssetsGeographicAreaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=us-gaap_EuropeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=country_CN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=al_AsiaExcludingChinaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=al_CentralAmericaSouthAmericaAndMexicoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=al_MiddleEastAndAfricaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=al_PacificAustraliaNewZealandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=al_NumberOfCustomersGeographicAreaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: