Reportable Segments (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Reportable Segments
Number of operating segments | segment		2
Revenue:
Lease rent revenue		$ 39,644	$ 30,233
Maintenance reserve revenue		15,440	31,961
Revenue From Sale Of Spare Parts		6,286	12,596
Gain on sale of leased equipment		640	983
Other Income		1,882	2,173
Total revenue		63,892	77,946
Expenses:
Depreciation and amortization expense		17,355	16,628
Cost of spare parts and equipment sales		4,783	10,318
Write-down of equipment			12,091
General and administrative		15,611	13,201
Technical expense		3,677	2,292
Interest Expense		13,595	10,865
Total expenses		55,021	65,395
Earnings from operations		8,871	12,551
Total assets	[1]	1,724,505		$ 1,603,431
Reclassification
Expenses:
Increase to Cost of spare parts and equipment sales		900	900
Decrease to Write-down of equipment		(900)
Operating Segments | Leasing and Related Operations
Revenue:
Lease rent revenue		39,644	30,233
Maintenance reserve revenue		15,440	31,961
Revenue From Sale Of Spare Parts			6,425
Gain on sale of leased equipment		640	983
Other Income		1,851	2,125
Total revenue		57,575	71,727
Expenses:
Depreciation and amortization expense		17,269	16,540
Cost of spare parts and equipment sales			4,705
Write-down of equipment			12,091
General and administrative		14,495	12,414
Technical expense		3,677	2,292
Interest Expense		13,595	10,865
Total expenses		49,036	58,907
Earnings from operations		8,539	12,820
Total assets		1,693,802		1,580,094
Operating Segments | Spare Parts Sales
Revenue:
Revenue From Sale Of Spare Parts		6,286	6,171
Other Income		1,113	175
Total revenue		7,399	6,346
Expenses:
Depreciation and amortization expense		86	88
Cost of spare parts and equipment sales		4,783	5,613
General and administrative		1,116	787
Total expenses		5,985	6,488
Earnings from operations		1,414	(142)
Total assets		30,703		$ 23,337
Eliminations
Revenue:
Other Income		(1,082)	(127)
Total revenue		(1,082)	(127)
Expenses:
Earnings from operations		$ (1,082)	$ (127)

[1] Total assets at March 31, 2018 and December 31, 2017, respectively, include the following assets of variable interest entities (VIEs) that can only be used to settle the liabilities of the VIEs: Cash, $595 and $130; Restricted Cash $44,511 and $40,272; Equipment, $653,809 and $657,333; and Other, $1,230 and $20,090, respectively.