Income Taxes - Deferred Taxes (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets:
Net operating loss	$ 83	$ 6,234
Deferred loss	0	1,440
Deferred revenue	5,829	5,985
Federal tax credits	0	3,176
Nondeductible accruals	6,744	5,452
Other	1,072	306
Gross deferred tax assets	13,728	22,593
Deferred tax assets, net	13,728	22,593
Deferred tax liabilities:
Capitalized interest	(1,125)	(2,041)
Deferred gain	(364)	0
Fuel hedging	(97)	(115)
Accrued engine maintenance	(29,497)	(10,232)
Property, plant, and equipment	(3,271)	(1,575)
Gross deferred tax liabilities	34,354	13,963
Net deferred tax assets (liabilities)	(20,626)	8,630
Assets:
Other current assets	12,591	20,738
Liabilities:
Other long-term liabilities	$ (33,216)	$ (12,108)