Investments (Details) (USD $)				0 Months Ended	1 Months Ended	12 Months Ended			36 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 18, 2013 WOLF item	Jun. 30, 2011 WMES engine	Dec. 31, 2013 WMES engine	Dec. 31, 2012 WMES	Dec. 31, 2011 WMES	Dec. 31, 2013 WMES engine	May 25, 2011 WMES	Dec. 31, 2013 WMES JA Mitsui Leasing, Ltd	Dec. 31, 2005 WOLF item	Dec. 31, 2013 WOLF item	Sep. 16, 2013 WOLF	Dec. 31, 2012 WOLF	Dec. 31, 2011 WOLF
Investments
Previously held interest (as a percent)														50.00%
Initial capital contribution										$ 8,000,000
Additional capital contributions						11,200,000	5,600,000	1,000,000
Number of engines transferred to the joint venture					7
Number of engines purchased									17
Number of engines in lease portfolio						26							8
Capital contributions to date						25,800,000			25,800,000
Proportionate gain on sale of engines to joint venture interest which is off-set against investments						3,600,000
Net investment after deducting partial offset						22,200,000			22,200,000
Gain on sale of engines					7,200,000
Credit facility established by equity method investee						62,000,000			62,000,000		180,000,000
Investment in joint venture	23,485,000	21,831,000	15,239,000			23,485,000	11,766,000	5,376,000	23,485,000						10,065,000	9,863,000
Number of Airbus A340-313 aircraft purchased												2
Purchase price of aircraft												96,000,000
Number of aircraft leased to Emirates												2
Acquisition of the remaining outstanding shares (as a percent)				50.00%
Purchase price consideration				1,000,000
Discount from JV partner's equity interest				12,700,000
Number of aircraft engines acquired				8
Number of aircraft airframes acquired				2
Fair value of the net assets acquired				12,600,000
Amount of equipment acquired				27,000,000
Amount of cash and receivables acquired				1,600,000
Amount of debt and other liabilities				$ 16,000,000
Controlling interest assumed (as a percent)				100.00%