Revenue (Tables)

6 Months Ended

Jun. 30, 2015

Revenue [Abstract]

Differentiation of revenue and cost of revenue

Revenue and cost of revenue by source are as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2015		2014		2015		2014
Revenue:
Products	$	74,522	$	82,302	$	140,682	$	164,707
Rentals	8,747		15,065		20,571		28,989
Services	3,761		7,951		8,151		14,197
	$	87,030	$	105,318	$	169,404	$	207,893
Cost of revenue:
Products	$	50,189	$	49,995	$	95,850	$	97,731
Rentals	3,687		7,654		9,943		14,165
Services	2,089		3,265		4,124		5,978
Depreciation	1,813		2,094		3,708		4,029
	$	57,778	$	63,008	$	113,625	$	121,903