Rental Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 146,009		$ 146,009		$ 141,388
Depreciation - Property, plant and equipment			9,407	$ 6,868
Rental Equipment
Property, Plant and Equipment [Line Items]
Accumulated depreciation	16,700		16,700		$ 14,600
Depreciation - Property, plant and equipment	$ 2,600	$ 2,200	$ 5,200	$ 4,300