Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Depreciable lives are summarized as follows:

Boeing 777, 767, 757 and 737 aircraft and flight equipment	7 to 18 years
Ground equipment	3 to 10 years
Leasehold improvements, facilities and office equipment	3 to 25 years

Property and equipment, to be held and used, is summarized as follows (in thousands):

	December 31, 2018			December 31, 2017
Flight equipment	$	2,340,840		$	1,801,808
Ground equipment	57,455			53,523
Leasehold improvements, facilities and office equipment	28,745			26,897
Aircraft modifications and projects in progress	74,449			121,760
	2,501,489			2,003,988
Accumulated depreciation	(946,484		)	(844,026		)
Property and equipment, net	$	1,555,005		$	1,159,962