Investments (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Jun. 03, 2014
Investments
Capital contribution				$ 5,545	$ 630
Investment in WMES joint ventures at beginning of the period				41,295
Earnings from joint venture				874
Deferred gain on engine sale				(1,212)
Distribution				(1,167)
Foreign currency translation adjustment		$ (2,547)	$ (304)	(2,021)	(304)
Investment in WMES joint ventures at end of the period		43,314		43,314
Management fees		$ 500	$ 400	$ 1,300	$ 1,200
WMES
Investments
Ownership interest (as a percent)		100.00%	50.00%	100.00%	50.00%
Capital contribution				$ 5,545
Investment in WMES joint ventures at beginning of the period				27,272
Earnings from joint venture				929
Deferred gain on engine sale				(1,212)
Distribution				(1,167)
Investment in WMES joint ventures at end of the period		$ 31,367		31,367
Gain on sale of equipemnt				$ 1,200
Amortized Gain Period				15 years
Amortized Gain Residual Value Percent				55.00%
Consolidated Statements of Income
Revenue		8,549	$ 7,067	$ 25,547	$ 19,997
Expenses		7,496	6,302	23,886	18,052
WMES net income		1,053	$ 765	1,661	$ 1,945
Consolidated Balance Sheets
Total assets		292,412		292,412		$ 256,126
Total liabilities		221,127		221,127		195,258
Total WMES net equity		71,285		71,285		$ 60,868
CASC
Investments
Ownership interest (as a percent)							50.00%
Capital contribution	$ 15,000
Investment in WMES joint ventures at beginning of the period				14,023
Earnings from joint venture				(55)
Foreign currency translation adjustment				(2,021)
Investment in WMES joint ventures at end of the period		$ 11,947		$ 11,947