Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net income (loss)		$ (472,569)	$ (428,700)	$ 335,255
Adjustments to reconcile net income (loss) to net cash provided by operations:
Losses reclassified from other comprehensive income		226	252	315
Share-based compensation		12,536	11,575	8,154
Allowance for doubtful accounts (recoveries)		(88)	(249)	0
Amortization of deferred gains, losses and debt issuance costs		12,912	10,752	8,654
Depreciation and amortization		297,211	278,588	225,264
Accretion of convertible debt and 8.00% senior secured notes		1,272	10,138	0
Deferred income tax expense (benefit)		(49,502)	(46,086)	115,689
Loss on disposal of assets		3,320	2,264	17,350
Loss on extinguishment of debt		331,630	0	0
Changes in operating assets and liabilities:
Accounts receivable, net		(85,800)	30,486	(26,147)
Aircraft maintenance deposits, net		52,486	23,732	22,453
Long-term deposits and other assets		(4,631)	(12,944)	14,999
Prepaid income taxes		156	(223)	1,431
Deferred heavy maintenance, net		(74,083)	(75,230)	(175,957)
Income tax receivable		109,570	(126,447)	(21,013)
Accounts payable		13,057	(17,052)	569
Air traffic liability		(19,649)	86,558	23,429
Other liabilities		80,103	27,194	1,698
Other		731	118	(822)
Net cash provided (used) by operating activities		208,888	(225,274)	551,321
Investing activities:
Purchase of available-for-sale investment securities		(105,361)	(118,893)	(122,410)
Proceeds from the maturity and sale of available-for-sale investment securities		104,500	117,665	120,830
Pre-delivery deposits on flight equipment, net of refunds		(119,352)	(143,220)	(102,102)
Capitalized interest		(17,258)	(12,233)	(10,774)
Assets under construction for others		(1,207)	(3,944)	(7,936)
Purchase of property and equipment		(213,767)	(393,375)	(334,537)
Net cash used in investing activities		(352,445)	(554,000)	(456,929)
Financing activities:
Proceeds from issuance of long-term debt		614,496	1,612,391	225,891
Proceeds from issuance of common stock and warrants		375,662	366,783	0
Proceeds from stock options exercised		0	39	1
Payments on debt obligations		(956,788)	(254,304)	(246,783)
Payments for the early extinguishment of debt		(317,905)	0	0
Payments on finance lease obligations		(831)	(25,401)	(96,547)
Reimbursement for assets under construction for others		996	4,153	5,618
Repurchase of common stock		(1,515)	(1,669)	(5,439)
Long-term debt and equity issuance costs		(2,775)	(40,551)	(2,909)
Net cash provided (used) by financing activities		(288,660)	1,661,441	(120,168)
Net increase (decrease) in cash, cash equivalents, and restricted cash		(432,217)	882,167	(25,776)
Cash, cash equivalents, and restricted cash at beginning of period	[1]	1,861,124	978,957	1,004,733
Cash, cash equivalents, and restricted cash at end of period	[1]	1,428,907	1,861,124	978,957
Cash payments for:
Interest, net of capitalized interest		135,500	80,837	80,254
Income taxes paid (received), net		(112,461)	(17,790)	5,843
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases		261,435	180,805	191,004
Financing cash flows for finance leases		93	194	674
Non-cash transactions:
Capital expenditures funded by finance lease borrowings		538	565	45,608
Capital expenditures funded by operating lease borrowings		$ 683,333	$ 168,526	$ 569,948

[1] The sum of cash and cash equivalents and restricted cash on our consolidated balance sheets equals cash, cash equivalents, and restricted cash in our statement of cash flows.