The Company and Summary of Significant Accounting Policies (Details) $ / shares in Units, shares in Thousands				1 Months Ended	12 Months Ended
	Feb. 18, 2018 USD ($) $ / shares	Feb. 16, 2017 $ / shares	Mar. 14, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) GB / s $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) shares	Feb. 15, 2018
Speed per second of high-speed interface technology of Bandwidth Engine ICs (in giga per second) | GB / s					10
Net loss					$ (10,668,000)	$ (32,048,000)	$ (31,483,000)
Accumulated deficit					(224,688,000)	(214,020,000)
Interest payments in-kind through the issuance of additional notes					$ 898,000	$ 650,000
Reverse stock split		10
Common Stock, Par or Stated Value Per Share | $ / shares		$ 0.001			$ 0.001	$ 0.001
Maximum specific allowance as percentage of invoice value for problematic customer balances					100.00%
Allowance for doubtful accounts receivable					$ 0	$ 0
Inventory reserves					$ 300,000	0	300,000
Impairment of goodwill						9,858,000
Threshold purchase return percentage by distributors for slow, non-moving or obsolete inventory					10.00%
Specified period for return of threshold percentage of purchases by distributors for slow, non-moving or obsolete inventory					6 months
Support and maintenance revenue recognition period					12 months
Licensing revenue					$ 0	$ 0	$ 0
Per Share Amounts
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares					2,427	1,640	907
Deferred tax assets					$ 69,507,000	$ 89,756,000
Valuation allowance					68,857,000	$ 89,428,000
ASU No. 2016-09
Per Share Amounts
Deferred tax assets					10,500,000
Valuation allowance					$ 10,500,000
Options
Per Share Amounts
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares					307	522	839
Employee stock purchase plan
Per Share Amounts
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares						44	44
RSU's
Per Share Amounts
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares					376	148	24
Convertible debt
Per Share Amounts
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares					1,081	926
Outstanding warrants
Per Share Amounts
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares					663
Senior Secured Convertible Notes due August 15 2018
Stated interest rate (as a percent)			10.00%	10.00%	10.00%			8.00%
Aggregate principal amount			$ 8,000,000	$ 8,000,000
Interest payments in-kind through the issuance of additional notes				$ 1,700,000
Conversion price (in dollars per share) | $ / shares	$ 4.25				$ 8.50
Redemption purchase price (as a percent)	100.00%				120.00%
Maximum amount of indebtedness subordinated by security interest and cash payment rights under debt instruments	$ 5,000,000		$ 5,000,000
Minimum
Estimated useful lives					3 years
Estimated useful life					3 years
Maximum
Estimated useful lives					5 years
Estimated useful life					7 years