Income Taxes - Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Income tax credits	$ 9,632	$ 10,004
Net operating losses	13,604	155,670
Deferred revenue	8,824	6,824
Nondeductible accruals	14,133	14,691
Deferred manufacturing credits	2,813	0
Accrued maintenance	1,668	2,168
Equity compensation	2,851	2,592
Lease liability	305,161
Valuation allowance	(1,746)	(254)
Other	482	5,262
Deferred tax assets	357,422	196,957
Deferred tax liabilities:
Deferred gain (loss) on leases, net	0	1,672
Accrued rent	0	6,068
Prepaid expenses	1,120	793
Property, plant and equipment	430,523	481,847
Deferred financing costs	154	189
Accrued aircraft and engine maintenance	84,479	61,529
Right-of-use asset	310,438
Deferred tax liabilities	826,714	552,098
Net deferred tax assets (liabilities)	$ (469,292)	$ (355,141)