CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CONSOLIDATED STATEMENTS OF CASH FLOWS
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 20,508	$ 231,593
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(595,325)	(332,865)
Sales of marketable securities	586,864	337,612
Acquisition of property and equipment:
Aircraft and rotable spare parts	(111,782)	(51,904)
Buildings and ground equipment	(2,236)	(4,224)
Proceeds from the sale of property and equipment	2,749	2,150
Deposits on aircraft	(28,031)	(5,000)
Aircraft deposits applied towards acquired aircraft	23,481
Increase in other assets	(387)	(67,176)
NET CASH USED IN INVESTING ACTIVITIES	(124,667)	(121,407)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt	185,740	39,931
Principal payments on long-term debt	(93,979)	(135,007)
Net proceeds from issuance of common stock	1,514	1,745
Employee income tax paid on vested equity awards	(1,123)	(1,573)
Payment of debt issuance cost	(413)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	91,739	(94,904)
Increase (decrease) in cash and cash equivalents	(12,420)	15,282
Cash and cash equivalents at beginning of period	258,421	215,723
CASH AND CASH EQUIVALENTS AT END OF PERIOD	246,001	231,005
Non-cash investing and financing activities:
Acquisition of property and equipment	13,567	1,380
Warrants issued to U.S. Treasury		3,291
Cash paid during the period for:
Interest, net of capitalized amounts	29,840	31,646
Income taxes	$ 116	$ 157