REVENUE RECOGNITION - Disaggregated Revenue (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 6,144,000	$ 7,030,000	$ 91,560,000	$ 16,254,000
Revenue, increase (decrease)	(886,000)		75,306,000
Revenue, increase (decrease), percent		(13.00%)		463.00%
Development, services, and other	152,000		233,000
Revenue, revenue recognized	1,200,000		1,800,000
Contract with customer, asset, current	5,100,000		5,100,000
Contract with customer, asset, noncurrent	4,100,000		4,100,000
Increase (decrease) in contract with customer, asset	(100,000)		4,300,000
Contract assets, impairment	0
Fixed fee license revenue
Disaggregation of Revenue [Line Items]
Revenue	1,881,000	$ 1,765,000	77,637,000	$ 4,275,000
Revenue, increase (decrease)	116,000		73,362,000
Revenue, increase (decrease), percent		7.00%		1716.00%
Per-unit royalty revenue
Disaggregation of Revenue [Line Items]
Revenue	4,111,000	$ 5,020,000	13,690,000	$ 11,516,000
Revenue, increase (decrease)	(909,000)		2,174,000
Revenue, increase (decrease), percent		(18.00%)		19.00%
Total royalty and license revenue
Disaggregation of Revenue [Line Items]
Revenue	5,992,000	$ 6,785,000	91,327,000	$ 15,791,000
Revenue, increase (decrease)	(793,000)		75,536,000
Revenue, increase (decrease), percent		(12.00%)		478.00%
Development, services, and other revenue
Disaggregation of Revenue [Line Items]
Revenue	152,000	$ 245,000	233,000	$ 463,000
Revenue, increase (decrease)	$ (93,000)		$ (230,000)
Revenue, increase (decrease), percent		(38.00%)		(50.00%)

Increase (Decrease) in Contract with Customer, Asset

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- Definition

Revenue from Contract with Customer, Excluding Assessed Tax, Increase (Decrease)

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No definition available.

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- Definition

Revenue from Contract with Customer, Excluding Assessed Tax, Percent Change

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No definition available.

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- Definition

Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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- Definition

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
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- Definition

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Revenue from providing technology services. The services may include training, installation, engineering or consulting. Consulting services often include implementation support, software design or development, or the customization or modification of the licensed software.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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