Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statutory Federal income tax rate (as a percent)	21.00%	21.00%	35.00%
Reconciliation
Computed provision for income taxes at the statutory rate	$ 93,724	$ 76,926	$ 100,864
State income tax provision, net of federal income tax benefit	15,645	12,711	7,778
Non-deductible expenses	3,934	1,956	3,230
Valuation allowance changes affecting the provision for income taxes	(517)	(1,187)	505
Foreign income taxes, net of federal & state benefit		1,192
Excess tax benefits from share based compensation	(3,525)	(4,548)	(5,377)
Revaluation of net deferred taxes for the Tax Cuts and Jobs Act of 2017			(246,845)
Other, net	(3,055)	(1,108)	(879)
Provision (benefit) for income taxes	106,206	85,942	(140,724)
Deferred tax assets:
Accrued benefits	20,848	32,462
Net operating loss carryforward	358,685	344,375
AMT credit carryforward	4,397	15,744
Aircraft credits	9,114	35,924
Accrued reserves and other	17,225	18,710
Total deferred tax assets	410,269	447,215
Valuation allowance	(892)	(9,455)
Deferred tax liabilities:
Accelerated depreciation	(1,032,957)	(955,919)
Total deferred tax liabilities	(1,032,957)	(955,919)
Net deferred tax liability	(623,580)	(518,159)
Accounting Standards Update 2016-09
Reconciliation
Benefit from share-based compensation	3,500	4,500	5,400
ExpressJet | State
Reconciliation
Valuation allowance	$ 500	$ 1,200	$ 500