Summary of Significant Accounting Policies - Contract Revenues (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended		10 Months Ended	19 Months Ended
	Oct. 31, 2020	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Sep. 30, 2024	Dec. 31, 2022	Dec. 31, 2021	Oct. 31, 2021	Dec. 31, 2020
Summary of Significant Accounting Policies [Line Items]
Receivables, net		$ 3,857,000		$ 3,857,000		$ 5,592,000	$ 3,857,000
Payments for proceeds from incentives and penalties		0		0
Deferred income		0		0		0	0
Fulfillment costs						774,000	774,000
Contract liabilities, net		1,648,000		1,648,000		100,000	1,648,000
Purchased services and other		3,567,000	$ 6,537,000	9,686,000	$ 18,511,000
Long-term contract liabilities, net		297,000	2,792,000	297,000	2,792,000	2,984,000	297,000	$ 0
Cash paid	$ 670,000
Accrued liabilities	$ 11,048,000
Cash received from united for the opening of a crew base										$ 294,000
Short-Term Contract with Customer
Summary of Significant Accounting Policies [Line Items]
Contract liabilities, net		1,545,000		1,545,000		662,000	1,545,000
Long-Term Contract with Customer
Summary of Significant Accounting Policies [Line Items]
Long-term contract liabilities, net		48,000		48,000		2,831,000	48,000
Minimum Crew Availability
Summary of Significant Accounting Policies [Line Items]
Revenue from crew availability minimums				1,998,000
Air Wisconsin
Summary of Significant Accounting Policies [Line Items]
Contract liabilities, net						3,493,000
United Airlines
Summary of Significant Accounting Policies [Line Items]
Receivables, net		0		0		0	0
Payments for proceeds from incentives and penalties			6,000		1,236,000
American Capacity Purchase Agreement | Heavy Maintenance Reimbursements
Summary of Significant Accounting Policies [Line Items]
Contract liabilities, net		2,099,000		2,099,000		562,000	2,099,000
Long-term contract liabilities, net						152,000
Revenue related to one-time assistance payment, estimated monthly support fee and heavy maintenance revenues				1,000
American Capacity Purchase Agreement | Pilot Compensation Assistance Payment
Summary of Significant Accounting Policies [Line Items]
Contract liabilities, net						562,000
Long-term contract liabilities, net		242,000		242,000		152,000	242,000
Revenue related to one-time assistance payment, estimated monthly support fee and heavy maintenance revenues				7,000
American Capacity Purchase Agreement | American Airlines | Air Wisconsin
Summary of Significant Accounting Policies [Line Items]
Rebates payable		207,000	0	862,000	0
October 2020 Amendment
Summary of Significant Accounting Policies [Line Items]
Deferred revenue recognition		0	0	0	649,000
Contract liabilities, net		0		0		0	0
Deferred cash payable											$ 4,410,000
Deferred revenue									$ 73,000
October 2020 Amendment | United Capacity Purchase Agreement
Summary of Significant Accounting Policies [Line Items]
Contract liabilities, net		0		0		$ 0	0
Related Party | Air Wisconsin
Summary of Significant Accounting Policies [Line Items]
Receivables, net		1,365,000		1,365,000			1,365,000
Deferred revenue recognition		0	0	0	11,601,000
Upfront fee		0	0	0	1,335,000
Fulfillment costs		0	0	0	143,000
Contract liabilities, net		1,593,000		1,593,000			1,593,000
Estimated non-refundable upfront fee revenue				3,998,000
Non-refundable upfront fee revenues		1,558,000	193,000	1,900,000	319,000
Revenue related to one-time assistance payment, estimated monthly support fee and heavy maintenance revenues		2,176,000	1,946,000	5,982,000	3,206,000
Related Party | Air Wisconsin | Minimum Crew Availability
Summary of Significant Accounting Policies [Line Items]
Deferred revenue recognition		3,819,000	0	3,901,000	0
Upfront Fee Received From Minimum Crew Availability		1,420,000		1,904,000
Additional fees to be received		14,623,000		14,623,000			$ 14,623,000
Related Party | American Capacity Purchase Agreement | Air Wisconsin
Summary of Significant Accounting Policies [Line Items]
Deferred revenue recognition		$ 21,792,000	$ 23,693,000	63,908,000	$ 37,057,000
Purchased services and other				$ 3,998,000
Revenue Benchmark | American Capacity Purchase Agreement | Customer Concentration Risk
Summary of Significant Accounting Policies [Line Items]
Concentration risk		100.00%	99.70%	100.00%	52.50%
Revenue Benchmark | United Capacity Purchase Agreement | Customer Concentration Risk
Summary of Significant Accounting Policies [Line Items]
Concentration risk			0.10%		47.30%