Operating Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 item	Jun. 30, 2013	Dec. 31, 2013
Operating Segments
Number of operating segments			2
Revenue:
Lease rent revenue	$ 24,801	$ 24,750	$ 51,701	$ 49,237
Maintenance reserve revenue	14,560	11,788	28,590	21,017
Spare parts sales	29		108
Gain on sale of leased equipment	1,591		1,821
Other revenue	1,270	567	3,031	1,469
Total revenue	42,251	37,953	85,251	73,257
Expenses:
Depreciation and amortization expense	15,735	14,191	31,445	27,801
General and administrative	9,261	9,204	18,947	17,473
Net finance costs	9,396	9,852	18,755	19,079
Other expense	4,553		6,368
Total expenses	38,945	39,448	75,515	72,228
Earnings (loss) from operations	3,306	(1,495)	9,736	1,029
Total assets	1,179,252		1,179,252		1,199,229
Leasing And Related Operations Segment [Member]
Revenue:
Lease rent revenue	24,801		51,701
Maintenance reserve revenue	14,560		28,590
Gain on sale of leased equipment	1,591		1,821
Other revenue	552		1,598
Total revenue	41,504		83,710
Expenses:
Depreciation and amortization expense	15,662		31,300
General and administrative	8,644		17,666
Net finance costs	9,396		18,755
Other expense	4,553		6,368
Total expenses	38,255		74,089
Earnings (loss) from operations	3,249		9,621
Total assets	1,176,045		1,176,045		1,194,800
Spare Parts Sales Segment [Member]
Revenue:
Spare parts sales	29		108
Other revenue	718		1,433
Total revenue	747		1,541
Expenses:
Depreciation and amortization expense	73		145
General and administrative	617		1,281
Total expenses	690		1,426
Earnings (loss) from operations	57		115
Total assets	$ 3,207		$ 3,207		$ 4,429