Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash Flows From Operating Activities
Net income	$ 32,366	$ 82,025
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and obsolescence allowance	19,957	19,569
Amortization of contract costs	(3,314)	(2,428)
Amortization of engine overhauls	2,098	1,364
Deferred income taxes	(118)	133
Loss on disposition of property and equipment	62	40
Loss on marketable securities	9,774	106
Gain on extinguishment of debt	(53)	(10,363)
Changes in operating assets and liabilities:
Accounts receivable	(25,850)	(2,425)
Notes Receivable	(12,747)	(13,699)
Spare parts and supplies	(149)	229
Prepaid expenses and other	3,699	(4,884)
Operating lease right-of-use asset	41	182
Accounts payable	(3,467)	5,109
Accrued payroll and employee benefits	(1,828)	(1,011)
Other accrued expenses	81	84
Long-term deferred revenue	(9,046)	(11,938)
Contract liabilities	(2,534)	(7,117)
Deferred revenue	(13,474)	27,961
Income taxes payable	4,633	(107)
Other long-term liabilities	35	(1)
Net Cash Provided by Operating Activities	166	82,829
Cash Flows From Investing Activities
Additions to property and equipment	(2,963)	(1,349)
Proceeds on disposition of property and equipment	10	15
Purchase of marketable securities	(1,921)	(204,126)
Sale of marketable securities		77,477
Net Cash Used in Investing Activities	(4,874)	(127,983)
Cash Flows From Financing Activities
Repayments of long-term debt	(2,184)	(39,466)
Dividends paid	(594)	(594)
Cancellation of stock option	(969)	0
Repurchase of common stock	(10,733)	(1,188)
Net Cash Used in Financing Activities	(14,480)	(41,248)
Decrease in Cash, Cash Equivalents and Restricted Cash	(19,188)	(86,402)
Cash, Cash Equivalents and Restricted Cash, beginning of period	38,619	131,193
Cash, Cash Equivalents and Restricted Cash, end of period	$ 19,431	$ 44,791