Summary of Significant Accounting Policies - Schedule of Statement of Operations Prior Period Adjustment to the Adoption of Topic 606 (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenues	$ 263,605	$ 240,610
Aircraft maintenance repair	57,827	55,118
Amortization expense	25,238	22,145
Loss from Operations	(20,862)	(24,498)
Income Tax (Benefit)	322	(5,124)
Net income	(19,214)	181,313
Contract Revenue [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenues	$ 263,495	240,552
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Aircraft maintenance repair		51,879
Amortization expense		21,745
Loss from Operations		(18,139)
Income Tax (Benefit)		(4,297)
Net income		186,845
Previously Reported [Member] | Contract Revenue [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenues		243,272
Revision of Prior Period, Change in Accounting Principle, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Aircraft maintenance repair		3,239
Amortization expense		400
Loss from Operations		(6,359)
Income Tax (Benefit)		(827)
Net income		(5,532)
Revision of Prior Period, Change in Accounting Principle, Adjustment [Member] | Contract Revenue [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenues		$ (2,720)