Allowance for credit losses (Narrative) (Details) $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($) category
Allowance For Credit Loss [Line Items]
Number of categories of financing receivables \| category	3
COVID-19 Pandemic & GECAS Transaction
Allowance For Credit Loss [Line Items]
Increase in allowance for credit loss \| $	$ 83.7

Allowance for Credit Loss, Period Increase (Decrease)

No definition available.

Name:	aer_AllowanceForCreditLossPeriodIncreaseDecrease
Namespace Prefix:	aer_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration