Fair Value Measurements - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) equipment engine	Jun. 30, 2020 USD ($) engine	Jun. 30, 2021 USD ($) equipment	Jun. 30, 2021 USD ($) equipment engine	Jun. 30, 2021 USD ($) airframe equipment	Jun. 30, 2020 USD ($) engine	Dec. 31, 2020 USD ($)
Derivative [Line Items]
Fair value of notes receivable	$ 198,000,000.0		$ 198,000,000.0	$ 198,000,000.0	$ 198,000,000.0		$ 159,200,000
Fair value of notes payable	1,926,800,000		1,926,800,000	$ 1,926,800,000	$ 1,926,800,000		1,691,000,000.0
Interest expense	16,987,000	$ 16,089,000	32,006,000			$ 31,785,000
Asset write-down	$ 2,200,000	$ 7,000,000.0	4,100,000			$ 9,100,000
Number of assets impaired	4			4	1
Remaining book value	$ 40,700,000		$ 40,700,000	$ 40,700,000	$ 40,700,000
Number of assets previously impaired | equipment	23		23	23	23
Assets to be Sold or Parted Out
Derivative [Line Items]
Number of assets impaired | engine		3				5
Impaired Assets
Derivative [Line Items]
Number of assets impaired | engine		2				2
Interest rate contract
Derivative [Line Items]
Net fair value of swap asset (liability)	$ 1,800,000		$ 1,800,000	$ 1,800,000	$ 1,800,000		$ (4,000,000.0)
Fair value of interest rate swap, asset	3,900,000		3,900,000	3,900,000	3,900,000
Fair value of interest rate swap, liability	2,100,000		2,100,000	$ 2,100,000	$ 2,100,000
Interest expense	$ 500,000	$ 600,000	$ 1,400,000			$ 600,000