Income Taxes - Summary of Unrecognized Tax Benefits and Temporary Differences (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Unrecognized tax benefits
Balance at the beginning of the period	$ 330	$ 270
Decreases related to current year tax positions	0	66
Decreases due to tax positions expired	(317)	(6)
Balance at the end of the period	13	330
Uncertain tax positions, reserved for tax exposure in Europe	0	300
Uncertain tax positions, reserved for tax exposure in Europe, released during the year	300
Deferred tax assets:
Unearned lease revenue	2,217	2,519
State taxes	0	10
Inventory	1,486	2,153
Reserves and allowances	6,781	4,356
Other accruals	2,577	1,769
Foreign tax credit	0	0
Lease liability	146	198
Net operating loss carry forward	68,168	74,045
California alternative minimum tax credit	33	33
Charitable contributions	2	65
Total deferred tax assets	81,410	85,148
Less: valuation allowance	(518)	(468)
Net deferred tax assets	80,892	84,680
Deferred tax liabilities:
Depreciation and impairment on aircraft engines and equipment	(183,131)	(163,773)
Inventory	0	0
Notes receivable	(15,911)	(34,426)
Right of use liability	(139)	(184)
Other deferred tax liabilities	(4,595)	(4,616)
Net deferred tax liabilities	(203,776)	(202,999)
Other comprehensive (income) loss deferred tax liability	(1,448)
Other comprehensive (income) loss deferred tax liability		1,481
Net deferred tax liabilities	(124,332)	$ (116,838)
Federal
Deferred tax liabilities:
Operating loss carryforwards	316,300
State
Deferred tax liabilities:
Operating loss carryforwards	2,200
State | California Franchise Tax Board
Deferred tax liabilities:
Valuation allowance of net operating loss	500
State | Georgia Department of Revenue
Deferred tax liabilities:
Valuation allowance of net operating loss	$ 100