Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Product	$ 128,056	$ 130,674	$ 226,986	$ 258,569
Services and other revenues	52,829	42,233	104,453	85,342
Total revenues	180,885	172,907	331,439	343,911
Cost of revenues:
Cost of product revenues	81,738	76,306	145,326	148,224
Cost of services and other revenues	21,172	18,584	43,946	37,725
Total cost of revenues	102,910	94,890	189,272	185,949
Gross profit	77,975	78,017	142,167	157,962
Operating expenses:
Research and development	16,911	13,794	33,714	27,632
Selling, general and administrative	63,468	64,341	128,093	128,596
Total operating expenses	80,379	78,135	161,807	156,228
Income (loss) from operations	(2,404)	(118)	(19,640)	1,734
Interest and other income (expense), net	196	(1,881)	(2,260)	(4,052)
Loss before provision for income taxes	(2,208)	(1,999)	(21,900)	(2,318)
Benefit from income taxes	(3,045)	(840)	(11,983)	(781)
Net income (loss)	$ 837	$ (1,159)	$ (9,917)	$ (1,537)
Net income (loss) per share:
Net loss per share - basic and diluted (in dollars per share)	$ 0.02	$ (0.03)	$ (0.27)	$ (0.04)
Weighted-average shares outstanding:
Weighted-average shares outstanding — basic (in shares)	37,250	35,987	37,046	35,864
Weighted-average shares outstanding — diluted (in shares)	38,370	35,987	37,046	35,864