Condensed Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 863,680	$ 700,900
Short-term investment securities	100,732	100,155
Accounts receivable, net	46,235	41,136
Aircraft maintenance deposits, net	166,386	87,035
Prepaid expenses and other current assets	67,707	46,619
Total current assets	1,244,740	975,845
Property and equipment:
Flight equipment	2,017,888	1,461,525
Ground property and equipment	148,324	126,206
Less accumulated depreciation	(183,065)	(122,509)
Total property and equipment	1,983,147	1,465,222
Deposits on flight equipment purchase contracts	304,732	325,688
Long-term aircraft maintenance deposits	138,672	199,415
Deferred heavy maintenance, net	87,566	75,534
Other long-term assets	112,085	110,223
Total assets	3,870,942	3,151,927
Current liabilities:
Accounts payable	30,961	15,193
Air traffic liability	276,933	206,392
Current maturities of long-term debt	105,958	84,354
Other current liabilities	249,132	226,011
Total current liabilities	662,984	531,950
Long-term debt, less current maturities	1,214,138	897,359
Deferred income taxes	406,080	308,143
Deferred gains and other long-term liabilities	17,204	19,868
Shareholders’ equity:
Common stock	7	7
Additional paid-in-capital	557,772	551,004
Treasury stock, at cost	(219,930)	(218,692)
Retained earnings	1,233,901	1,063,633
Accumulated other comprehensive loss	(1,214)	(1,345)
Total shareholders’ equity	1,570,536	1,394,607
Total liabilities and shareholders’ equity	$ 3,870,942	$ 3,151,927