Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 1,947,619	$ 978,957
Restricted cash	54,838	0
Short-term investment securities	106,324	105,321
Accounts receivable, net	51,182	73,807
Aircraft maintenance deposits, net	70,934	102,906
Income tax receivable	146,961	21,013
Prepaid expenses and other current assets	121,252	103,439
Total current assets	2,499,110	1,385,443
Property and equipment:
Flight equipment	4,126,302	3,730,751
Ground property and equipment	328,093	291,998
Less accumulated depreciation	(631,685)	(492,447)
Total property and equipment, net	3,822,710	3,530,302
Operating lease right-of-use assets	1,408,106	1,369,555
Pre-delivery deposits on flight equipment	374,830	291,930
Long-term aircraft maintenance deposits	54,047	67,682
Deferred heavy maintenance, net	362,596	361,603
Other long-term assets	35,895	36,897
Total assets	8,557,294	7,043,412
Current liabilities:
Accounts payable	36,068	43,601
Air traffic liability	429,892	315,408
Current maturities of long-term debt and finance leases	373,300	258,852
Current maturities of operating leases	130,793	120,662
Other current liabilities	326,650	373,521
Total current liabilities	1,296,703	1,112,044
Long-term debt and finance leases, less current maturities	3,074,900	1,960,453
Operating leases, less current maturities	1,242,843	1,218,014
Deferred income taxes	486,487	469,292
Deferred gains and other long-term liabilities	52,258	22,277
Shareholders’ equity:
Common stock	28	7
Additional paid-in-capital	796,553	379,380
Treasury stock, at cost	(74,052)	(72,455)
Retained earnings	1,682,182	1,955,187
Accumulated other comprehensive income (loss)	(608)	(787)
Total shareholders’ equity	2,404,103	2,261,332
Total liabilities and shareholders’ equity	$ 8,557,294	$ 7,043,412