Operating Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) segment	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Operating segments
Number of operating segments | segment	2
Revenue:
Lease rent revenue	$ 30,233	$ 28,276
Maintenance reserve revenue	31,961	15,819
Spare parts sales	12,596	2,632
Gain on sale of leased equipment	983	2,992
Other revenue	2,173	1,000
Total revenue	77,946	50,719
Expenses:
Depreciation and amortization expense	16,628	16,419
Cost Of Spare Parts and Equipment Sales	9,400	1,932
Write-down of equipment	13,009	2,036
General and administrative	13,201	11,752
Technical expense	2,292	1,696
Net finance costs	10,865	10,008
Total expenses	65,395	43,843
Earnings from operations	12,551	6,876
Total assets	1,322,989		$ 1,337,887
Operating Segments [Member] | Leasing and Related Operations
Revenue:
Lease rent revenue	30,233	28,276
Maintenance reserve revenue	31,961	15,819
Spare parts sales	6,425
Gain on sale of leased equipment	983	2,992
Other revenue	2,125	933
Total revenue	71,727	48,020
Expenses:
Depreciation and amortization expense	16,540	16,337
Cost Of Spare Parts and Equipment Sales	4,705
Write-down of equipment	12,091	2,036
General and administrative	12,414	10,980
Technical expense	2,292	1,696
Net finance costs	10,865	9,913
Total expenses	58,907	40,962
Earnings from operations	12,820	7,058
Total assets	1,293,122		1,307,460
Operating Segments [Member] | Spare Parts Sales
Revenue:
Spare parts sales	6,171	2,632
Other revenue	175	358
Total revenue	6,346	2,990
Expenses:
Depreciation and amortization expense	88	82
Cost Of Spare Parts and Equipment Sales	4,695	1,932
Write-down of equipment	918
General and administrative	787	772
Net finance costs		95
Total expenses	6,488	2,881
Earnings from operations	(142)	109
Total assets	29,867		$ 30,427
Intersegment Eliminations [Member]
Revenue:
Other revenue	(127)	(291)
Total revenue	(127)	(291)
Expenses:
Earnings from operations	$ (127)	$ (291)