Condensed Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Net cash provided by operating activities	$ 97,420	$ 37,902
Investing activities:
Proceeds from sale of property, equipment and slots	9,074	5,537
Pre-delivery deposits for flight equipment, net of refunds	4,738	(20,091)
Purchase of property and equipment, net	(19,218)	(7,305)
Net cash used in investing activities	(5,406)	(21,859)
Financing activities:
Proceeds from issuance of common stock	303	171,014
Payments on debt	0	(20,564)
Proceeds from sale leaseback transactions	5,627	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	(856)	(757)
Debt issuance costs	0	8
Net cash provided by (used in) financing activities	(20,365)	149,701
Net increase in cash and cash equivalents	71,649	165,744
Cash and cash equivalents at beginning of period	343,328	82,714
Cash and cash equivalents at end of period	414,977	248,458
Cash Payments for:
Interest paid	287	2,615
Taxes paid	21,819	187
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	$ 35,889