Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Payables and Accruals [Abstract]
Aircraft maintenance	$ 21,029	$ 7,816
Federal excise and other passenger taxes and fees payable	20,962	17,813
Salaries and wages	17,232	17,123
Airport expenses	12,120	10,682
Fuel	9,592	87
Current portion of tax receivable agreement	9,484	27,399
Aircraft and facility rent	7,993	7,206
Other	11,398	10,730
Accrued liabilities	$ 109,810	$ 98,856