Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:
Net income	$ 176,918	$ 108,460	$ 76,448
Adjustments to reconcile net income to net cash provided by operations:
Changes in fair value of open fuel hedge contracts	265	46	3,204
Non-cash restructuring credit charges, net	0	0	0
Equity based stock compensation, net	5,689	4,327	530
Allowance for doubtful accounts	143	78	27
Amortization of deferred gains, losses and debt issuance costs	(558)	(830)	(1,047)
Depreciation and amortization	31,947	15,256	7,760
Deferred income tax benefit	12,047	29,255	44,180
Loss on disposal of assets	525	956	255
Gain on slot sale	0	(9,060)	0
Interest and dividends incurred but not paid	0	0	21,875
Capitalized interest	(214)	(1,350)	(2,890)
Changes in operating assets and liabilities:
Restricted cash	0	0	72,736
Accounts receivable	(461)	(7,393)	(5,728)
Prepaid maintenance reserves	(24,058)	(31,567)	(36,848)
Long-term deposits and other assets	(65,654)	(68,248)	(15,992)
Accounts payable	(1,674)	8,452	2,457
Air traffic liability	36,226	19,134	6,573
Other liabilities	24,235	46,115	(2,189)
Other	0	0	(153)
Net cash provided by operating activities	195,376	113,631	171,198
Investing activities:
Proceeds from sale of property and equipment	0	14	150
Proceeds from sale of slots	0	9,060	0
Pre-delivery deposits for flight equipment, net of refunds	(70,288)	(12,626)	(53,274)
Purchase of property and equipment	(19,812)	(23,771)	(14,093)
Net cash used in investing activities	(90,100)	(27,323)	(67,217)
Financing activities:
Proceeds from issuance of common stock, net of offering expenses	0	0	170,828
Proceeds from options exercised	852	469	423
Payments on debt	0	0	(18,221)
Proceeds from sale and leaseback transactions	6,900	12,540	4,481
Payments to pre-IPO shareholders pursuant to tax receivable agreement	0	(26,905)	0
Excess tax benefits from share-based compensation	1,927	2,098	0
Repurchase of common stock	(1,140)	(1,022)	(886)
Debt issuance costs	0	0	8
Net cash provided by (used in) financing activities	8,539	(12,820)	156,633
Net increase in cash and cash equivalents	113,815	73,488	260,614
Cash and cash equivalents at beginning of period	416,816	343,328	82,714
Cash and cash equivalents at end of period	530,631	416,816	343,328
Cash payments for:
Interest	29	303	10,562
Taxes	85,705	40,204	1,477
Non-cash transactions:
Exchange of notes due to related parties for common stock	0	0	279,206
Exchange of mandatorily redeemable preferred stock for common stock	0	0	81,747
Liability and equity related to tax receivable agreement	(2,336)	(1,497)	36,522
Capital expenditures funded by capital lease borrowings	$ (3,234)	$ 0	$ 0