Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended
	Jun. 30, 2012 aircraft_slot	Dec. 31, 2011
Payables and Accruals [Abstract]
Federal excise and other passenger taxes and fees payable	$ 27,383	$ 17,813
Salaries and wages	18,381	17,123
Airport expenses	13,693	10,682
Aircraft maintenance	10,575	7,816
Fuel	10,288	87
Current portion of tax receivable agreement	9,490	27,399
Deferred gain on sale of slots	9,060	0
Aircraft and facility rent	7,096	7,206
Restructuring	234	329
Other	11,279	10,401
Accrued liabilities	$ 117,479	$ 98,856
Number of permanent air carrier slots transferred	4