Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Payables and Accruals [Abstract]
Aircraft maintenance	$ 36,165	$ 22,319
Federal excise and other passenger taxes and fees payable	26,979	23,401
Salaries and wages	26,174	21,057
Airport expenses	17,109	16,024
Fuel	13,819	11,219
Aircraft and facility rent	7,993	8,020
Tax receivable agreement	5,643	7,987
Other	11,380	11,287
Other current liabilities	$ 145,262	$ 121,314