Defined Contribution 401(k) Plan (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) defined_contribution_plan	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Defined contribution 401(k) plan, number of plans | defined_contribution_plan	3
Defined contribution 401(k) plan, requisite service period	60 days
Defined contribution 401(k) plan, requisite age	21 years
Defined contribution 401(k) plan, matching contributions made in period | $	$ 12.5	$ 9.7	$ 7.7
Employee Retirement Savings Plan
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of match	50.00%
Employee Retirement Savings Plan | Maximum
Defined Contribution Plan Disclosure [Line Items]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	3.00%
Pilots’ Retirement Savings Plan
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of match	100.00%
Pilots’ Retirement Savings Plan | Maximum
Defined Contribution Plan Disclosure [Line Items]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	9.00%
Puerto Rico Retirement Savings Plan | Pilots
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of match	100.00%
Puerto Rico Retirement Savings Plan | Other Employees
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of match	50.00%
Puerto Rico Retirement Savings Plan | Maximum | Pilots
Defined Contribution Plan Disclosure [Line Items]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	9.00%
Puerto Rico Retirement Savings Plan | Maximum | Other Employees
Defined Contribution Plan Disclosure [Line Items]
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	3.00%