Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 aircraft	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies
Number of aircraft leased by the entity	570
Future minimum rental payments required under operating leases
2014	$ 380,413,000
2015	331,151,000
2016	258,464,000
2017	194,258,000
2018	153,294,000
Thereafter	571,783,000
Total	1,889,363,000
Rental expense for non-cancelable aircraft operating leases	325,360,000	333,637,000	346,526,000
Minimum rental expense for airport station rents	$ 35,100,000	$ 43,500,000	$ 42,600,000
Leveraged lease agreements term, maximum	12 years