Rental Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (110,321)		$ (110,321)		$ (107,094)
Depreciation			9,155	$ 9,361
Rental Equipment
Property, Plant and Equipment [Line Items]
Accumulated depreciation	(9,832)		(9,832)		$ (8,322)
Depreciation	$ 1,699	$ 1,918	$ 3,443	$ 3,664