Variable interest entities (Narrative) (Details) - Variable Interest Entity, Primary Beneficiary $ in Millions	6 Months Ended
Jun. 30, 2020 USD ($)
AerFunding
Variable Interest Entity [Line Items]
Ownership percentage	100.00%
Ownership percentage	5.00%
Credit facility amount outstanding	$ 1,945.0
Senior debt facility	$ 795.7
AerCap Partners I and Aercap Partners 767
Variable Interest Entity [Line Items]
Ownership percentage	50.00%
AerCap Partners I
Variable Interest Entity [Line Items]
Subordinated debt	$ 54.4
Aercap Partners 767
Variable Interest Entity [Line Items]
Subordinated debt	$ 32.6
Deucalion Aviation Funds \| AerCap Partners I and Aercap Partners 767
Variable Interest Entity [Line Items]
Ownership percentage	50.00%
Deucalion Aviation Funds \| AerCap Partners I
Variable Interest Entity [Line Items]
Subordinated debt	$ 27.2
Deucalion Aviation Funds \| Aercap Partners 767
Variable Interest Entity [Line Items]
Subordinated debt	16.3
AerCap Partners I \| AerCap Holdings N.V.
Variable Interest Entity [Line Items]
Subordinated debt	27.2
Aercap Partners 767 \| AerCap Holdings N.V.
Variable Interest Entity [Line Items]
Subordinated debt	$ 16.3

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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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.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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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.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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