Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,004,733	$ 800,849
Short-term investment securities	102,789	100,937
Accounts receivable, net	47,660	49,323
Aircraft maintenance deposits, net	106,901	175,615
Income tax receivable	0	69,844
Prepaid expenses and other current assets	83,383	85,542
Total current assets	1,345,466	1,282,110
Property and equipment:
Flight equipment	3,257,215	2,291,110
Ground property and equipment	191,661	155,166
Less accumulated depreciation	(332,864)	(207,808)
Total property and equipment	3,116,012	2,238,468
Pre-delivery deposits on flight equipment	236,775	253,687
Long-term aircraft maintenance deposits	138,738	150,617
Deferred heavy maintenance, net	249,010	99,915
Other long-term assets	79,456	121,003
Total assets	5,165,457	4,145,800
Current liabilities:
Accounts payable	39,320	22,822
Air traffic liability	291,981	263,711
Current maturities of long-term debt and capital leases	163,557	115,430
Other current liabilities	339,677	262,370
Total current liabilities	834,535	664,333
Long-term debt and capital leases, less current maturities	2,024,774	1,387,498
Deferred income taxes	355,141	308,814
Deferred gains and other long-term liabilities	22,503	22,581
Shareholders’ equity:
Common stock: Common stock, $0.0001 par value, 240,000,000 shares authorized at December 31, 2018 and 2017, respectively; 69,871,535 and 69,770,795 issued and 68,269,567 and 68,196,964 outstanding as of December 31, 2018 and 2017, respectively	7	7
Additional paid-in-capital	371,225	360,153
Treasury stock, at cost: 1,601,968 and 1,573,831 shares as of December 31, 2018 and 2017, respectively	(67,016)	(65,854)
Retained earnings	1,625,481	1,469,732
Accumulated other comprehensive income (loss)	(1,193)	(1,464)
Total shareholders’ equity	1,928,504	1,762,574
Total liabilities and shareholders’ equity	$ 5,165,457	$ 4,145,800