Related Party Transactions (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Related Party Transaction [Line Items]
Net charter income (expense)	$ 232,405,000	$ 220,813,000
Percentage of tax benefits realized payable	85.00%
Tax receivable agreement, liability	56,300,000
Tax receivable agreement, liability, discount rate	5.31%
Affiliated Entity
Related Party Transaction [Line Items]
Rent expense	1,900,000	1,900,000
Western Airlines
Related Party Transaction [Line Items]
Net charter income (expense)	$ (400,000)	$ 300,000