Condensed Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 818,110	$ 700,900
Short-term investment securities	100,294	100,155
Accounts receivable, net	48,692	41,136
Aircraft maintenance deposits	125,758	87,035
Prepaid expenses and other current assets	53,677	46,619
Total current assets	1,146,531	975,845
Property and equipment:
Flight equipment	1,608,959	1,461,525
Ground property and equipment	136,126	126,206
Less accumulated depreciation	(140,535)	(122,509)
Total property and equipment	1,604,550	1,465,222
Deposits on flight equipment purchase contracts	330,523	325,688
Long-term aircraft maintenance deposits	170,631	199,415
Deferred heavy maintenance, net	71,870	75,534
Other long-term assets	114,509	110,223
Total assets	3,438,614	3,151,927
Current liabilities:
Accounts payable	39,612	15,193
Air traffic liability	308,958	206,392
Current maturities of long-term debt	92,672	84,354
Other current liabilities	231,932	226,011
Total current liabilities	673,174	531,950
Long-term debt, less current maturities	991,722	897,359
Deferred income taxes	327,660	308,143
Deferred gains and other long-term liabilities	17,712	19,868
Shareholders’ equity:
Common stock	7	7
Additional paid-in-capital	553,820	551,004
Treasury stock, at cost	(219,726)	(218,692)
Retained earnings	1,095,568	1,063,633
Accumulated other comprehensive loss	(1,323)	(1,345)
Total shareholders’ equity	1,428,346	1,394,607
Total liabilities and shareholders’ equity	$ 3,438,614	$ 3,151,927