Debt, Related-Party Transactions and Other Obligations - Debt (Narrative) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Line of Credit Facility [Line Items]
Debt outstanding	$ 0	$ 0
Due to related parties, current	0	0
Line of credit | Corporate credit cards
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	18,600,000	8,600,000
Line of credit, amount outstanding	3,200,000	2,400,000
Line of credit | Aircraft fuel
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	18,000,000
Line of credit | Jet fuel derivatives
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	5,000,000	8,000,000
Line of credit, amount outstanding	0	0
Line of credit | Jet fuel delivery
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	10,000,000
Line of credit, amount outstanding	11,200,000
Line of credit | Jet fuel derivatives and/or delivery
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	3,000,000
Line of credit, amount outstanding	$ 0