Condensed Statements Of Cash Flows (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Activities
Net Income	$ 37,706	$ 30,554
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Unrealized mark-to-market losses (gains)	0	3,381
Equity-based compensation, net	2,547	1,420
Allowance for Doubtful Accounts	(13)	26
Amortization of deferred gains and losses	(89)	(195)
Depreciation and amortization	11,121	6,324
Deferred income tax benefit	410	2,532
Loss on disposal of assets	150	170
Capitalized interest	(107)	(9)
Changes in operating assets and liabilities
Accounts receivable	(10,656)	(1,902)
Prepaid maintenance reserves	(14,661)	(6,803)
Long-term deposits and other assets	(15,691)	(11,741)
Accounts payable	1,457	(7,335)
Air traffic liability	62,328	44,390
Other liabilities	16,137	24,381
Net cash provided by operating activities	90,639	85,193
Investing activities:
Pre-delivery deposits for flight equipment, net of refunds	(73,201)	(15,127)
Purchase of property and equipment	(4,086)	(10,588)
Net cash used in investing activities	(77,287)	(25,715)
Financing activities:
Proceeds from options exercised	39	449
Proceeds from sale and leaseback transactions	0	6,900
Excess tax benefits from equity-based compensation	588	162
Repurchase of common stock	(621)	(321)
Net cash provided by financing activities	6	7,190
Net increase in cash and cash equivalents	13,358	66,668
Cash and cash equivalents at beginning of period	530,631	416,816
Cash and cash equivalents at end of period	543,989	483,484
Cash payments for:
Interest	0	9
Taxes	$ 3,218	$ 932