Revenue (Tables)

6 Months Ended

Jun. 30, 2013

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,
	2013		2012		2013		2012
Revenue:
Products	$	71,523	$	56,425	$	127,853	$	113,681
Rentals	15,679		16,981		31,419		35,047
Services	6,384		4,897		12,557		8,770
	$	93,586	$	78,303	$	171,829	$	157,498
Cost of revenue:
Products	$	46,992	$	34,136	$	81,508	$	68,620
Rentals	4,281		7,497		10,798		15,507
Services	2,832		1,831		5,569		3,391
Depreciation	1,887		1,814		3,730		3,504
	$	55,992	$	45,278	$	101,605	$	91,022