Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(4))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The Company and Summary of Significant Accounting Policies - Summary of Impact of Adoption of Accounting Standards on Condensed Consolidated Balance Sheet (Details) - USD ($)	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts receivable, net	$ 1,505,000		$ 1,681,000
Stockholders’ equity
Accumulated deficit	(224,110,000)		(224,688,000)
Adjustments due to ASC 606 [Member] \| ASU 2014-09 [Member]
Assets
Accounts receivable, net	1,285,000		230,000
Stockholders’ equity
Accumulated deficit	(224,330,000)	$ 230,000	230,000
Effect of Adoption Higher (Lower) [Member] \| ASU 2014-09 [Member]
Assets
Accounts receivable, net	(220,000)		1,911,000
Stockholders’ equity
Accumulated deficit	$ (220,000)		$ (224,458,000)