Income Taxes - Deferred Taxes (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Net operating loss	$ 188	$ 83
Deferred loss	1,428	0
Deferred revenue	6,241	5,829
Nondeductible accruals	9,734	6,744
Other	2,767	1,073
Deferred tax assets	20,358	13,729
Deferred tax liabilities:
Capitalized interest	736	1,125
Deferred gain	0	364
Fuel hedging	0	97
Accrued engine maintenance	45,911	29,497
Property, plant and equipment	6,384	3,271
Deferred tax liabilities	53,031	34,354
Net deferred tax assets (liabilities)	(32,673)	(20,625)
Assets:
Other current assets	16,243	12,591
Liabilities:
Other long-term liabilities	$ 48,916	$ 33,216