Investments (Details) (USD $)	9 Months Ended		1 Months Ended	9 Months Ended	12 Months Ended			42 Months Ended			1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2011 Willis Mitsui and Company, Engine Support Limited [Member] engine	Sep. 30, 2014 Willis Mitsui and Company, Engine Support Limited [Member] item	Dec. 31, 2013 Willis Mitsui and Company, Engine Support Limited [Member]	Dec. 31, 2012 Willis Mitsui and Company, Engine Support Limited [Member]	Dec. 31, 2011 Willis Mitsui and Company, Engine Support Limited [Member]	Sep. 30, 2014 Willis Mitsui and Company, Engine Support Limited [Member] engine	May 25, 2011 Willis Mitsui and Company, Engine Support Limited [Member]	Jun. 03, 2014 CASC Willis Engine Lease Company Limited [Member]	Oct. 31, 2014 CASC Willis Engine Lease Company Limited [Member] Subsequent Event [Member]
Investments
Ownership percentage				50.00%				50.00%		50.00%
Initial capital contribution									$ 8,000,000
Number of engines transferred to the joint venture			7
Capital contributions					11,200,000	5,600,000	1,000,000
Number of engines purchased								17
Capital contributions to date				28,400,000				28,400,000
Proportionate gain on sale of engines to joint venture interest which is off-set against investments			3,600,000
Gain on sale of engines				7,200,000
Net investment after deducting partial offset				24,800,000				24,800,000
Investment in joint venture				26,427,000	23,485,000			26,427,000
Number of engines in lease portfolio				26
Capital contribution to joint ventures	$ (2,623,000)	$ (6,145,000)		$ (2,623,000)							$ 15,000,000