PROPERTY AND EQUIPMENT Property and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation	$ 2,700	$ 2,700	$ 5,800	$ 4,400
Property and equipment	69,905		69,905		$ 76,846
Accumulated depreciation	(38,930)		(38,930)		(40,705)
Property and equipment, net	30,975		30,975		36,141
Property, Plant and Equipment, Disposals			1,300
Aircraft
Property, Plant and Equipment [Line Items]
Property and equipment	29,853		29,853		27,567
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	22,803		22,803		23,506
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Property and equipment	5,471		5,471		7,778
Software development costs
Property, Plant and Equipment [Line Items]
Property and equipment	2,111		2,111		2,111
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 9,667		$ 9,667		$ 15,884