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Fair Value Measurements - Additional Information (Details) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 USD ($) equipment | Sep. 30, 2020 USD ($) engine | Sep. 30, 2021 USD ($) equipment | Sep. 30, 2021 USD ($) equipment engine | Sep. 30, 2021 USD ($) equipment airframe | Sep. 30, 2020 USD ($) engine | Dec. 31, 2020 USD ($)
Derivative [Line Items] |  |  |  |  |  |  |
Fair value of notes receivable | $ 198,500,000 |  | $ 198,500,000 | $ 198,500,000 | $ 198,500,000 |  | $ 159,200,000
Fair value of notes payable | 1,862,200,000 |  | 1,862,200,000 | $ 1,862,200,000 | $ 1,862,200,000 |  | 1,691,000,000
Interest expense | 18,325,000 | $ 15,351,000 | 50,331,000 |  |  | $ 47,136,000 |
Asset write-down | 0 | $ 5,200,000 | 4,100,000 |  |  | $ 14,400,000 |
Number of assets impaired |  |  |  | 4 | 1 |  |
Remaining book value | $ 30,700,000 |  | $ 30,700,000 | $ 30,700,000 | $ 30,700,000 |  |
Number of assets previously impaired | equipment | 16 |  | 16 | 16 | 16 |  |
Assets to be Sold or Parted Out |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Number of assets impaired | engine |  | 6 |  |  |  | 10 |
Impaired Assets |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Number of assets impaired | engine |  |  |  |  |  | 2 |
Interest rate contract |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Net fair value of swap asset (liability) | $ 2,400,000 |  | $ 2,400,000 | $ 2,400,000 | $ 2,400,000 |  | $ (4,000,000)
Fair value of interest rate swap, asset | 4,200,000 |  | 4,200,000 | 4,200,000 | 4,200,000 |  |
Fair value of interest rate swap, liability | 1,800,000 |  | 1,800,000 | $ 1,800,000 | $ 1,800,000 |  |
Interest expense | $ 500,000 | $ 700,000 | $ 1,900,000 |  |  | $ 1,300,000 |

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