Represents the number of additional term facilities entered into by the entity.

No definition available.

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

- Definition

The remaining time until maturity of the debt instrument.

+ References

No definition available.

+ Details

Name:	al_DebtInstrumentRemainingTerm
Namespace Prefix:	al_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of debt discount and debt issuance costs that were originally recognized at the issuance of the instrument that have yet to be amortized.

+ References

No definition available.

+ Details

Name:	al_DebtInstrumentUnamortizedDiscountAndIssuanceCosts
Namespace Prefix:	al_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount maturing on a line of credit.

+ References

No definition available.

+ Details

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

- Definition

Incremental borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of aircraft pledged as collateral.

+ References

No definition available.

+ Details

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

- Definition

Amount of debt for which lender has the rights to pledged collateral and also from the debtor's other assets in the event that the borrower is unable to satisfy debt obligation.

+ References

No definition available.

+ Details

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

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

+ Details

Name:	us-gaap_DebtConversionOriginalDebtAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

Amount of assets pledged to secure a debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Amount of debt for which creditor does not have general recourse to the debtor but rather has recourse only to the property used for collateral in the transaction or other specific property.

+ References

No definition available.

+ Details

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

- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=al_ThreeMonthLondonInterbankOfferedRateLiborMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgram4.25PercentDue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgram3.75PercentDue2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgramDue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgram2.25PercentDue2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgram3.25PercentDue2029Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgram2.30PercentDue2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_MediumTermNoteProgram3.00PercentDue2030Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UnsecuredTermFinancingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UnsecuredTermFinancingOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UnsecuredTermFinancingTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UnsecuredTermFinancingThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UnsecuredTermFinancing1.125PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UnsecuredTermFinancing3.00PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_UncommittedUnsecuredRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_SyndicatedUnsecuredRevolvingCreditFacilityMatureOn5May2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_SyndicatedUnsecuredRevolvingCreditFacilityMatureOn5may2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_SyndicatedUnsecuredRevolvingCreditFacilityMatureOn5May2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_SyndicatedUnsecuredRevolvingCreditFacilityMatureOn5May2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_ConvertibleNotesPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_SeniorUnsecuredNotes2.625PercentDue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CurrencySwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_SecuredTermFinancingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_ExportCreditFinancingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_FixedRateTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=al_FloatingRateTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt Financing (Details) $ in Millions		1 Months Ended	12 Months Ended
Debt Financing (Details) $ in Millions	May 05, 2019 USD ($)	Nov. 30, 2011 USD ($) shares	Dec. 31, 2019 CAD ($) item aircraft	Dec. 31, 2018 USD ($) aircraft	Jan. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) item aircraft	Apr. 30, 2019 USD ($)	Mar. 31, 2013 USD ($)
Debt financing
Total debt financing				$ 11,662,253,000		$ 13,721,295,000
Less: Debt discounts and issuance costs				(123,348,000)		(142,429,000)
Debt financing, net of discounts and issuance costs				11,538,905,000		13,578,866,000
Unsecured Debt
Debt financing
Total debt financing				11,252,785,000		13,260,861,000
Senior Notes
Debt financing
Total debt financing				$ 10,043,445,000		$ 12,357,811,000
Senior Notes \| LIBOR
Secured Obligations
Interest margin (as a percent)			1.125%
Senior Notes \| Three-Month LIBOR
Secured Obligations
Interest margin (as a percent)			0.67%
Senior Notes \| Minimum
Secured Obligations
Interest rate (as a percent)			2.125%	2.125%		2.125%
Remaining term (in years)			14 days
Senior Notes \| Maximum
Secured Obligations
Interest rate (as a percent)			4.85%	7.375%		4.85%
Remaining term (in years)			9 years 9 months 3 days
Medium Term Note Program
Secured Obligations
Principal amount issued					$ 1,400,000,000	$ 2,850,000,000
Medium Term Note Program 4.25 Percent Due 2024
Secured Obligations
Principal amount issued						$ 700,000,000.0
Interest rate (as a percent)			4.25%			4.25%
Medium Term Note Program 3.75 Percent Due 2026 [Member]
Secured Obligations
Principal amount issued						$ 750,000,000.0
Interest rate (as a percent)			3.75%			3.75%
Medium Term Note Program Due 2021 [Member]
Secured Obligations
Principal amount issued						$ 300,000,000.0
Medium Term Note Program Due 2021 [Member] \| Three-Month LIBOR
Secured Obligations
Interest rate (as a percent)			0.67%			0.67%
Medium Term Note Program 2.25 Percent Due 2023 [Member]
Secured Obligations
Principal amount issued						$ 600,000,000.0
Interest rate (as a percent)			2.25%			2.25%
Medium Term Note Program 3.25 Percent Due 2029 [Member]
Secured Obligations
Principal amount issued						$ 500,000,000.0
Interest rate (as a percent)			3.25%			3.25%
Medium Term Note Program 2.30 Percent Due 2025 [Member]
Secured Obligations
Principal amount issued					$ 750,000,000.0
Interest rate (as a percent)					2.30%
Medium Term Note Program 3.00 Percent Due 2030 [Member]
Secured Obligations
Principal amount issued					$ 650,000,000.0
Interest rate (as a percent)					3.00%
Unsecured Term financings
Debt financing
Total debt financing				$ 607,340,000		$ 883,050,000
Secured Obligations
Principal amount issued						$ 205,000,000.0
Interest rate (as a percent)			3.00%			3.00%
Number of additional term facilities entered into \| item			3
Unsecured Term financings \| Minimum
Secured Obligations
Interest rate (as a percent)			2.75%			2.75%
Remaining term (in years)			1 month 2 days
Unsecured Term financings \| Minimum \| LIBOR
Secured Obligations
Interest margin (as a percent)			0.95%
Unsecured Term financings \| Maximum
Secured Obligations
Interest rate (as a percent)			3.50%			3.50%
Remaining term (in years)			4 years 9 months
Unsecured Term financings \| Maximum \| LIBOR
Secured Obligations
Interest margin (as a percent)			1.125%
Unsecured Term Financing One
Secured Obligations
Principal amount issued						$ 80,000,000.0
Debt term			1 year
Unsecured Term Financing One \| LIBOR
Secured Obligations
Interest margin (as a percent)			1.00%
Unsecured Term Financing Two
Secured Obligations
Debt term			3 years
Unsecured Term Financing Two \| Three-Month LIBOR
Secured Obligations
Principal amount issued						75,000,000.0
Interest margin (as a percent)			1.00%
Unsecured Term Financing Three
Secured Obligations
Principal amount issued						50,000,000.0
Debt term			1 year
Unsecured Term Financing Three \| LIBOR
Secured Obligations
Interest margin (as a percent)			1.00%
Unsecured Term Financing 1.125 Percent
Secured Obligations
Principal amount issued				518,000,000.0		600,000,000.0
Incremental borrowing capacity						82,000,000.0
Debt term			4 years
Interest margin (as a percent)			1.125%
Unsecured Term Financing 3.00 Percent
Secured Obligations
Principal amount issued				5,400,000		$ 25,000,000.0
Interest rate (as a percent)			3.00%			3.00%
Incremental borrowing capacity						$ 19,600,000
Debt term			4 years
Uncommitted Unsecured Revolving Credit Facility [Member]
Secured Obligations
Principal amount issued						175,000,000.0
Revolving commitments held by lenders						0
Uncommitted Unsecured Revolving Credit Facility [Member] \| LIBOR
Secured Obligations
Interest margin (as a percent)			0.75%
Revolving Credit Facilities
Debt financing
Total debt financing				602,000,000		$ 20,000,000
Secured Obligations
Maximum borrowing capacity					$ 6,000,000,000.0		$ 4,900,000,000
Incremental borrowing capacity					$ 125,000,000.0		$ 310,000,000.0
Unsecured Revolving Credit Facility Maturing on May 5, 2020
Secured Obligations
Line of credit maturity amount	$ 92,700,000
Unsecured Revolving Credit Facility Mature On 5 May 2021
Secured Obligations
Revolving commitments held by lenders	5,000,000.0
Unsecured Revolving Credit Facility Mature On 5 May 2022
Secured Obligations
Revolving commitments held by lenders	245,000,000.0
Unsecured Revolving Credit Facility Mature On 5 May 2023
Secured Obligations
Maximum borrowing capacity	5,800,000,000
Incremental borrowing capacity	58,000,000.0
Revolving commitments held by lenders	$ 5,500,000,000
Facility fee (as a percent)	0.20%
Unsecured Revolving Credit Facility Mature On 5 May 2023 \| LIBOR
Secured Obligations
Interest margin (as a percent)	1.05%
Convertible Senior Notes
Debt financing
Total debt financing		$ 151,000
Secured Obligations
Principal amount issued		$ 200,000,000.0
Interest rate (as a percent)		3.875%
Convertible Senior Notes \| Class A Common Stock
Secured Obligations
Conversion of convertible notes to Class A Common Stock		$ 199,800,000
Issuance of shares on conversion \| shares		6,838,546
Senior Unsecured Notes 2.625 Percent Due 2024
Secured Obligations
Principal amount issued			$ 400.0
Interest rate (as a percent)			2.625%			2.625%
Senior Unsecured Notes 2.625 Percent Due 2024 \| Currency Swap
Secured Obligations
Interest rate (as a percent)			2.535%			2.535%
Secured Debt
Debt financing
Total debt financing				409,468,000		$ 460,434,000
Secured Obligations
Nonrecourse				167,245,000		128,460,000
Recourse				242,223,000		331,974,000
Total				$ 409,468,000		$ 460,434,000
Number of aircraft pledged as collateral \| aircraft			15	20		15
Net book value of aircraft pledged as collateral				$ 1,132,111,000		$ 890,693,000
Secured Term Financings \| Minimum
Secured Obligations
Remaining term (in years)			25 days
Secured Term Financings \| Maximum
Secured Obligations
Remaining term (in years)			9 years 10 months 2 days
Export Credit Financing
Debt financing
Total debt financing				38,265,000		31,610,000
Debt financing, net of discounts and issuance costs				38,300,000		31,600,000
Secured Obligations
Principal amount issued								$ 76,500,000
Interest rate (as a percent)								1.617%
Term Financings
Debt financing
Total debt financing				$ 371,203,000		$ 428,824,000
Secured Obligations
Number of aircraft pledged as collateral			15	18		15
Net book value of aircraft pledged as collateral				$ 1,100,000,000		$ 890,700,000,000
Fixed rate debt
Debt financing
Total debt financing				$ 500,000		$ 54,600,000
Secured Obligations
Interest rate (as a percent)			2.36%	4.58%		2.36%
Floating rate debt
Debt financing
Total debt financing				$ 370,700,000		$ 374,300,000
Floating rate debt \| Minimum \| LIBOR
Secured Obligations
Interest margin (as a percent)			0.80%	1.15%
Floating rate debt \| Maximum \| LIBOR
Secured Obligations
Interest margin (as a percent)			2.50%	2.99%