Reportable Segments (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2019 USD ($) segment.	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Reportable Segments
Number of reportable segments | segment.		2
Number of operating segments | segment.		2
Revenue:
Lease rent revenue		$ 48,369	$ 39,644
Maintenance reserve revenue		25,350	15,440
Spare parts and equipment sales		17,502	12,986
Gain on sale of leased equipment		9,570	545
Other revenue		2,978	1,882
Total revenue		103,769	70,497
Expenses:
Depreciation and amortization expense		20,258	17,355
Cost of spare parts and equipment sales		14,412	11,388
Write-down of equipment		1,105	0
General and administrative		21,440	15,611
Technical expense		1,788	3,677
Interest expense		17,879	13,595
Total expenses		76,882	61,626
Earnings from operations		26,887	8,871
Total assets	[1]	1,905,502		$ 1,934,943
Operating Segments | Leasing and Related Operations
Revenue:
Lease rent revenue		48,369	39,644
Maintenance reserve revenue		25,350	15,440
Spare parts and equipment sales		2,485	0
Gain on sale of leased equipment		9,570	545
Other revenue		2,978	1,851
Total revenue		88,752	57,480
Expenses:
Depreciation and amortization expense		20,236	17,269
Cost of spare parts and equipment sales		1,836	0
Write-down of equipment		1,105	0
General and administrative		19,974	14,495
Technical expense		1,787	3,677
Interest expense		17,879	13,595
Total expenses		62,817	49,036
Earnings from operations		25,935	8,444
Total assets		1,851,884		1,882,860
Operating Segments | Spare Parts Sales
Revenue:
Lease rent revenue		0	0
Maintenance reserve revenue		0	0
Spare parts and equipment sales		15,017	12,986
Gain on sale of leased equipment		0	0
Other revenue		94	1,113
Total revenue		15,111	14,099
Expenses:
Depreciation and amortization expense		22	86
Cost of spare parts and equipment sales		12,576	11,388
Write-down of equipment		0	0
General and administrative		1,466	1,116
Technical expense		1	0
Interest expense		0	0
Total expenses		14,065	12,590
Earnings from operations		1,046	1,509
Total assets		53,618		52,083
Eliminations
Revenue:
Lease rent revenue		0	0
Maintenance reserve revenue		0	0
Spare parts and equipment sales		0	0
Gain on sale of leased equipment		0	0
Other revenue		(94)	(1,082)
Total revenue		(94)	(1,082)
Expenses:
Depreciation and amortization expense		0	0
Cost of spare parts and equipment sales		0	0
Write-down of equipment		0	0
General and administrative		0	0
Technical expense		0	0
Interest expense		0	0
Total expenses		0	0
Earnings from operations		(94)	$ (1,082)
Total assets		$ 0		$ 0

[1] Total assets at March 31, 2019 and December 31, 2018, respectively, include the following assets of variable interest entities (“VIEs”) that can only be used to settle the liabilities of the VIEs: Cash $268 and $656; Restricted cash $68,072 and $70,261; Equipment $1,020,182 and $1,032,599; and Other assets $328 and $1,075, respectively.