Note C - Significant Customers (Details Textual) $ / shares in Units, $ in Thousands						3 Months Ended			6 Months Ended
	May 06, 2024 USD ($) $ / shares shares	Aug. 14, 2023 shares	Aug. 13, 2023 USD ($) shares	May 29, 2020 $ / shares shares	Dec. 22, 2018 $ / shares shares	Jun. 30, 2024 USD ($) shares	Jun. 30, 2023 USD ($)	Sep. 30, 2022	Jun. 30, 2024 USD ($) shares	Jun. 30, 2023 USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 20, 2018 shares	Mar. 18, 2016
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)						27,600,000			27,600,000
Gain (Loss) on Derivative Instruments, Net, Pretax | $						$ 2,946	$ 1,818		$ 5,301	$ 78
Stock Repurchased During Period, Shares (in shares)		5,435,777
Payments for Repurchase of Common Stock | $									(0)	36,874
Warrants and Sale Options [Member]
Gain (Loss) on Derivative Instruments, Net, Pretax | $						$ 2,700	$ (300)		$ 2,800	$ (1,100)
Warrants With Investment Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	21,800,000			7,000,000	14,800,000								14,800,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 20.4	$ 21.53
Class of Warrant or Right, Additional Number of Securities Called by Warrants or Rights (in shares)				2,900,000
Lessee, Number of Leased Aircraft				5
Adjustments to Additional Paid in Capital, Warrants Reclassified | $	$ 66,800
B-767-300 [Member]
Lessor, Number of Leased Aircraft				12							11	10
Lessor, Leased Aircraft, Lease Term (Year)				10 years
B-767 [Member]
Number of Additional Leased Aircraft												10
Lessor, Leased Aircraft, Number of Lease Extensions												20
DHL [Member] | B-767-200 [Member]
Lessor, Number of Leased Aircraft						1			1
DHL [Member] | B-767-300 [Member]
Lessor, Number of Leased Aircraft						13			13
DHL [Member] | B-767 [Member]
Number of Aircraft Operated								4
ASI [Member] | B-767-200 [Member]
Lessor, Number of Leased Aircraft					12
Lessor, Leased Aircraft, Lease Term (Year)					2 years
Lessor, Leased Aircraft, Option to Extend, Term (Year)					3 years
ASI [Member] | B-767-300 [Member]
Lessor, Number of Leased Aircraft					8
Number of Aircraft Operated					10
Lessor, Leased Aircraft, Lease Term (Year)					3 years
Lessor, Leased Aircraft, Option to Extend, Term (Year)					3 years
ASI [Member] | B-767 [Member]
Lessor, Number of Leased Aircraft						30			30
ATSA [Member] | The 2024 Subsequent Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	2,900,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 12.9658
Warrants and Rights Outstanding, Term (Year)	7 years
ATSA [Member] | The 2024 Subsequent Warrant [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	728,750
ATSA [Member] | ATSA [Member]
Lessor, Leased Aircraft, Lease Term (Year)					3 years
Agreement, Term (Year)					5 years
ATSA [Member] | B-767-300 [Member]
Lessor, Number of Leased Aircraft	10
Lessor, Leased Aircraft, Option to Extend, Term (Year)	5 years
Amazon [Member]
Lessor, Leased Aircraft, Option to Extend, Term (Year)	3 years
Shares Outstanding, Maximum Percentage of Shares Owned Allowed to Vote at Its Own Discretion														14.90%
Stock Repurchased During Period, Shares (in shares)			1,177,000
Payments for Repurchase of Common Stock | $			$ 22,900
Amazon [Member] | Third Subsequent Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	2,900,000
Warrants and Rights Outstanding, Term (Year)	7 years
Amazon [Member] | Third Subsequent Warrant [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	291,500
Amazon [Member] | Third Subsequent Warrant [Member] | Share-Based Payment Arrangement, Tranche Two [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	72,875
Amazon [Member] | The 2016 Investment Agreement Warrants [Member] | Maximum [Member]
Class of Warrant or Right, Percentage of Outstanding Shares to Be Acquired	19.50%													19.90%