Operating Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Revenue:
Lease rent revenue	$ 25,097	$ 26,900
Maintenance reserve revenue	14,148	14,030
Spare parts sales	2,151	418
Gain on sale of leased equipment	662	231
Other revenue	756	1,761
Total revenue	42,814	43,340
Expenses:
Depreciation and amortization expense	17,705	15,710
Cost of spare parts sales	1,480	340
General and administrative	9,972	9,685
Net finance costs	8,416	9,359
Other expense	1,856	1,815
Total expenses	39,429	36,909
Interest expense	9,567	9,359
Earnings from operations	3,385	6,431
Total assets	1,259,726		1,261,626
Operating Segments [Member] | Leasing and Related Operations
Revenue:
Lease rent revenue	25,097	26,900
Maintenance reserve revenue	14,148	14,030
Gain on sale of leased equipment	662	231
Other revenue	617	1,046
Total revenue	40,524	42,207
Expenses:
Depreciation and amortization expense	17,633	15,638
General and administrative	9,337	9,021
Net finance costs	8,326	9,359
Other expense	1,856	1,815
Total expenses	37,152	35,833
Earnings from operations	3,372	6,374
Total assets	1,240,865		1,241,837
Operating Segments [Member] | Spare Parts Sales
Revenue:
Spare parts sales	2,151	418
Other revenue	295	715
Total revenue	2,446	1,133
Expenses:
Depreciation and amortization expense	72	72
Cost of spare parts sales	1,480	340
General and administrative	635	664
Net finance costs	90
Total expenses	2,277	1,076
Earnings from operations	169	57
Total assets	18,861		19,789
Intersegment Eliminations [Member]
Revenue:
Other revenue	(156)
Total revenue	(156)
Expenses:
Earnings from operations	$ (156)