Condensed Statements Of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating activities:
Net income	$ 145,706	$ 102,555
Adjustments to reconcile net income to net cash provided by operations:
Unrealized (gains) losses on open fuel derivative contracts, net	4,257	0
Equity-based compensation, net	4,743	3,872
Allowance for doubtful accounts (recoveries)	8	(33)
Amortization of deferred gains and losses	397	(178)
Depreciation and amortization	32,002	22,465
Deferred income tax expense (benefit)	559	(395)
Loss on disposal of assets	1,010	865
Capitalized interest	(5,362)	(210)
Changes in operating assets and liabilities:
Accounts receivable	(8,137)	(14,188)
Prepaid maintenance reserves	(4,621)	(14,286)
Long-term deposits and other assets	(10,930)	(27,020)
Accounts payable	7,856	(1,462)
Air traffic liability	90,056	64,331
Other liabilities	39,327	7,819
Net cash provided by operating activities	296,871	144,135
Investing activities:
Pre-delivery deposits for flight equipment, net of refunds	(70,971)	(94,009)
Purchase of property and equipment	(308,163)	(7,430)
Net cash used in investing activities	(379,134)	(101,439)
Financing activities:
Proceeds from issuance of long-term debt	296,000	0
Proceeds from stock options exercised	23	63
Payments on debt and capital lease obligations	(8,940)	(511)
Sale Leaseback Transaction, Gross Proceeds, Financing Activities	7,300	0
Payments to pre-IPO shareholders pursuant to tax receivable agreement	0	(5,643)
Excess tax benefits from equity-based compensation	8,504	1,225
Repurchase of common stock	(79,415)	(1,222)
Debt issuance costs	(4,669)	0
Net cash provided by financing activities	218,803	(6,088)
Net increase in cash and cash equivalents	136,540	36,608
Cash and cash equivalents at beginning of period	632,784	530,631
Cash and cash equivalents at end of period	769,324	567,239
Cash payments for:
Interest (net of capitalized interest)	1,758	326
Taxes	$ 54,198	$ 52,093