Condensed Statements Of Cash Flows (unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Statement of Cash Flows [Abstract]
Net cash provided by operating activities	$ 88,807	$ 149,488
Investing activities:
Proceeds from sale of slots	9,060	0
Proceeds from sale of property and equipment	14	5,604
Pre-delivery deposits for flight equipment, net of refunds	(6,817)	(27,194)
Purchase of property and equipment	(21,711)	(9,573)
Net cash used in investing activities	(19,454)	(31,163)
Financing activities:
Proceeds from exercise of stock options	410	419
Proceeds from issuance of common stock	0	170,828
Payments on debt	0	(20,564)
Proceeds from sale leaseback transactions	12,427	0
Payments to pre-IPO shareholders pursuant to tax receivable agreement	(26,905)	0
Excess tax benefits from share-based compensation	1,466	0
Repurchase of restricted common stock	(936)	(757)
Debt issuance costs	0	8
Net cash (used in) provided by financing activities	(13,538)	149,934
Net increase in cash and cash equivalents	55,815	268,259
Cash and cash equivalents at beginning of period	343,328	82,714
Cash and cash equivalents at end of period	399,143	350,973
Cash Payments for:
Interest paid	297	8,219
Taxes paid	39,350	379
Non-cash transactions
Exchange of Notes due to related parties for common stock	0	279,206
Exchange of mandatorily redeemable preferred stock for common stock	0	81,747
Liability and offsetting reduction to equity recorded related to tax receivable agreement	$ 0	$ 36,522