Income Taxes (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statutory Federal income tax rate (as a percent)	35.00%
Reconciliation between the statutory Federal income tax rate of 35% and the effective rate which is derived by dividing the provision (benefit) for income taxes by income (loss) before provision for income taxes
Computed provision (benefit) for income taxes at the statutory rate	$ (5,720,000)	$ 34,486,000	$ 30,064,000
State income tax provision (benefit), net of Federal income tax benefit	(107,000)	2,867,000	2,220,000
Non-deductible expenses	3,865,000	3,257,000	2,919,000
Valuation allowance changes affecting the provision for income taxes	5,981,000	1,430,000	1,614,000
Foreign income taxes, net of federal & state benefit	1,973,000
Other, net	1,819,000	(2,464,000)	(2,078,000)
Provision for income taxes	7,811,000	39,576,000	34,739,000
Deferred tax assets:
Intangible Asset	34,819,000	36,164,000
Accrued benefits	43,853,000	40,850,000
Net operating loss carryforward	152,361,000	85,885,000
AMT credit carryforward	17,590,000	17,649,000
Deferred aircraft credits	53,797,000	44,350,000
Accrued reserves and other	27,008,000	30,987,000
Total deferred tax assets	329,428,000	255,885,000
Valuation allowance	(9,025,000)	(3,044,000)
Deferred tax liabilities:
Accelerated depreciation	(895,405,000)	(824,149,000)
Total deferred tax liabilities	(895,405,000)	(824,149,000)
Net deferred tax liability	(575,002,000)	(571,308,000)
Paint Facility [Member]
Reconciliation between the statutory Federal income tax rate of 35% and the effective rate which is derived by dividing the provision (benefit) for income taxes by income (loss) before provision for income taxes
Unrecorded tax benefits	$ 3,400,000