Reportable Segments (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment.	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Reportable Segments
Number of reportable segments | segment.				2
Number of operating segments | segment.				2
Revenue:
Lease rent revenue		$ 88,263	$ 66,354	$ 233,482	$ 186,565
Maintenance reserve revenue		39,173	19,370	90,998	56,855
Gain on sale of leased equipment		4,589	1,065	19,279	1,662
Total revenue		120,366	80,958	319,932	230,157
Expenses:
Depreciation and amortization expense		22,736	19,861	63,037	55,600
Cost of spare parts and equipment sales		20,195	8,832	47,192	30,524
Write-down of equipment		6,954	1,215	11,321	4,793
General and administrative		23,257	18,124	66,086	50,517
Technical expense		1,739	2,290	4,934	9,199
Interest expense		16,572	17,885	51,232	46,617
Loss on debt extinguishment		0	0	220	0
Total net finance costs		16,572	17,885	51,452	46,617
Total expenses		91,453	68,207	244,022	197,250
Earnings from operations		28,913	12,751	75,910	32,907
Total assets	[1]	1,930,435		1,930,435		$ 1,934,943
Operating Segments | Leasing and Related Operations
Revenue:
Lease rent revenue		88,263	66,354	233,482	186,565
Gain on sale of leased equipment		4,589	1,065	19,279	1,662
Total revenue		105,533	69,429	275,754	193,943
Expenses:
Depreciation and amortization expense		22,716	19,771	62,975	55,336
Cost of spare parts and equipment sales		7,825	0	9,913	0
Write-down of equipment		6,954	1,215	11,321	4,793
General and administrative		22,081	17,003	61,974	47,181
Technical expense		1,739	2,290	4,933	9,199
Interest expense		16,572	17,885	51,232	46,617
Loss on debt extinguishment				220
Total net finance costs				51,452
Total expenses		77,887	58,164	202,568	163,126
Earnings from operations		27,646	11,265	73,186	30,817
Total assets		1,884,127		1,884,127		1,882,860
Operating Segments | Spare Parts Sales
Revenue:
Lease rent revenue		0	0	0	0
Gain on sale of leased equipment		0	0	0	0
Total revenue		14,898	11,803	44,360	37,764
Expenses:
Depreciation and amortization expense		20	90	62	264
Cost of spare parts and equipment sales		12,370	8,832	37,279	30,524
Write-down of equipment		0	0	0	0
General and administrative		1,176	1,121	4,112	3,336
Technical expense		0	0	1	0
Interest expense		0	0	0	0
Loss on debt extinguishment				0
Total net finance costs				0
Total expenses		13,566	10,043	41,454	34,124
Earnings from operations		1,332	1,760	2,906	3,640
Total assets		46,308		46,308		52,083
Eliminations
Revenue:
Lease rent revenue		0	0	0	0
Gain on sale of leased equipment		0	0	0	0
Total revenue		(65)	(274)	(182)	(1,550)
Expenses:
Depreciation and amortization expense		0	0	0	0
Cost of spare parts and equipment sales		0	0	0	0
Write-down of equipment		0	0	0	0
General and administrative		0	0	0	0
Technical expense		0	0	0	0
Interest expense		0	0	0	0
Loss on debt extinguishment				0
Total net finance costs				0
Total expenses		0	0	0	0
Earnings from operations		(65)	(274)	(182)	(1,550)
Total assets		0		0		$ 0
Lease rent revenue
Revenue:
Lease rent revenue		49,090	46,984	142,484	129,710
Lease rent revenue | Operating Segments | Leasing and Related Operations
Revenue:
Lease rent revenue		49,090	46,984	142,484	129,710
Lease rent revenue | Operating Segments | Spare Parts Sales
Revenue:
Lease rent revenue		0	0	0	0
Lease rent revenue | Eliminations
Revenue:
Lease rent revenue		0	0	0	0
Maintenance reserve revenue
Revenue:
Lease rent revenue		39,173	19,370	90,998	56,855
Maintenance reserve revenue | Operating Segments | Leasing and Related Operations
Revenue:
Lease rent revenue		39,173	19,370	90,998	56,855
Maintenance reserve revenue | Operating Segments | Spare Parts Sales
Revenue:
Lease rent revenue		0	0	0	0
Maintenance reserve revenue | Eliminations
Revenue:
Lease rent revenue		0	0	0	0
Spare parts and equipment sales
Revenue:
Maintenance reserve revenue		24,409	11,529	56,497	36,168
Spare parts and equipment sales | Operating Segments | Leasing and Related Operations
Revenue:
Maintenance reserve revenue		9,583	0	12,334	0
Spare parts and equipment sales | Operating Segments | Spare Parts Sales
Revenue:
Maintenance reserve revenue		14,826	11,529	44,163	36,168
Spare parts and equipment sales | Eliminations
Revenue:
Maintenance reserve revenue		0	0	0	0
Other revenue
Revenue:
Maintenance reserve revenue		3,105	2,010	10,674	5,762
Other revenue | Operating Segments | Leasing and Related Operations
Revenue:
Maintenance reserve revenue		3,098	2,010	10,659	5,716
Other revenue | Operating Segments | Spare Parts Sales
Revenue:
Maintenance reserve revenue		72	274	197	1,596
Other revenue | Eliminations
Revenue:
Maintenance reserve revenue		$ (65)	$ (274)	$ (182)	$ (1,550)

[1] Total assets at September 30, 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 $148 and $656; Restricted cash $71,330 and $70,261; Equipment $1,013,944 and $1,032,599; and Other assets $711  and $1,075, respectively.