Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 16,787	$ 20,776
Restricted cash	775	755
Marketable securities	93,274	92,747
Receivables, net	3,739	5,592
Sales lease receivable, net	857	753
Spare parts and supplies, net	6,409	4,810
Contract costs	118	111
Prepaid expenses and other	2,100	2,115
Total Current Assets	124,059	127,659
Property and Equipment
Flight property and equipment	260,983	260,471
Ground property and equipment	8,811	8,792
Less accumulated depreciation and amortization	(200,617)	(193,457)
Net Property and Equipment	69,177	75,806
Long-Term Assets
Operating lease right-of-use asset	9,101	10,270
Intangibles	5,300	5,300
Long-term lease receivable, net	1,034	1,171
Long-term investments	4,275	4,275
Long-term contract costs	544	578
Long-term restricted investments (SESP)	3,480	3,194
Other	8,103	8,051
Total Long-Term Assets	31,837	32,839
Total Assets	225,073	236,304
Current Liabilities
Accounts payable	13,664	12,385
Accrued payroll and employee benefits	11,140	11,495
Current portion of operating lease liability	4,360	4,938
Other accrued expenses	138	67
Contract liabilities, net	331	100
Total Current Liabilities	29,633	28,985
Long-Term Liabilities
Long-term promissory note	4,275	4,275
Deferred tax liability	1,749	1,983
Long-term operating lease liability	2,476	3,010
Long-term contract liabilities, net	2,859	2,984
Long-term deferred compensation (SESP)	3,480	3,216
Other	1,782	2,007
Total Long-Term Liabilities	16,621	17,475
Total Liabilities	46,254	46,460
Commitments and Contingencies (Note 7)
Mezzanine Equity (Note 10)
Series C Convertible Redeemable Preferred Stock, $0.01 par value per share, 4,000,000 shares authorized, issued and outstanding at March 31, 2024 and December 31, 2023	13,200	13,200
Stockholders’ Equity
Common Stock, $0.01 par value per share, 100,000,000 shares authorized, 55,481,140 shares issued at March 31, 2024 and December 31, 2023, 42,653,887 shares outstanding at March 31, 2024 and 43,126,355 shares outstanding at December 31, 2023	555	555
Additional paid-in capital	283,874	284,340
Retained deficit	(98,286)	(88,719)
Treasury stock	(20,524)	(19,532)
Total Stockholders’ Equity	165,619	176,644
Total Liabilities, Mezzanine Equity, and Stockholders’ Equity	$ 225,073	$ 236,304