Rental Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2015
Rental Equipment [Abstract]
Rental equipment, primarily wireless recording equipment	$ 55,734				$ 68,959	$ 75,359
Accumulated depreciation and impairment	(39,272)				(37,986)	(29,323)
Rental equipment, net	$ 16,462	$ 20,551	$ 24,485	$ 26,821	$ 30,973	$ 46,036