Fair Value Measurements - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021 USD ($) airframe equipment	Mar. 31, 2020 USD ($) engine	Dec. 31, 2020 USD ($)
Derivative [Line Items]
Fair value of notes receivable	$ 201,300,000		$ 159,200,000
Fair value of notes payable	1,757,100,000		1,691,000,000.0
Increase in interest expense	900,000	$ 36,000.0
Asset write-down	$ 1,900,000	$ 2,100,000
Number of assets impaired	1	3
Remaining book value	$ 44,600,000
Number of assets previously impaired | equipment	22
Interest rate contract
Derivative [Line Items]
Net fair value of swap liability	$ 2,500,000		$ (4,000,000.0)
Fair value of interest rate swap, asset	4,900,000
Fair value of interest rate swap, liability	$ 2,300,000