Change in fair value of investment

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- Definition

Gain on Conversion of Loan and Accrued Interest

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No definition available.

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- Definition

Gain on exercise of Primary Warrant

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No definition available.

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- Definition

Investment at Fair Value Purchases and Issues

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No definition available.

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- Definition

Investments at fair value

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No definition available.

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- Definition

Lag time in recognizing revenues from licensees' quarter

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No definition available.

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Period after quarter end licensees report activity

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- Definition

Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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No definition available.

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Disclosure of the weighted average expected dividend for an entity using a valuation technique with different dividend rates during the contractual term.

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- Definition

Weighted average expected volatility rate of share-based compensation awards.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2018
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 3,000,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 104,754,000	$ 0
Investments at fair value	104,754,000	0
Short-term investments	$ 0	$ 19,443,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.00%	1.00%
Fair Value Assumptions, Expected Term	4 years 135 days	3 years 22 days
Lag time in recognizing revenues from licensee's quarter	3 months
Fair Value Assumptions, Weighted Average Volatility Rate	51.00%	53.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Expected Dividend	$ 0	$ 0
Gain on Conversion of Loan and Accrued Interest	2,671,000	0	$ 0
Gain on exercise of Primary Warrant	4,616,000	0	0
Change in fair value of investment	42,239,000	0	$ 0
Investment at Fair Value Purchases and Issues	$ 55,228,000
Minimum [Member]
Period after quarter end licensees report activity	30 days
Patents, useful life	1 year
Maximum [Member]
Period after quarter end licensees report activity	45 days
Patents, useful life	6 years
Fair Value, Inputs, Level 2 [Member]
Investments at fair value	$ 0
Short-term investments	0
Fair Value, Inputs, Level 3 [Member]
Investments at fair value	0
Short-term investments	104,754,000
Fair Value, Inputs, Level 1 [Member]
Investments at fair value	19,443,000
Short-term investments	0
Warrant [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	13,959,000	0
Gain on Conversion of Loan and Accrued Interest	0
Gain on exercise of Primary Warrant	(4,616,000)
Change in fair value of investment	8,317,000
Investment at Fair Value Purchases and Issues	1,026,000
Common Stock [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	90,795,000	$ 0
Gain on Conversion of Loan and Accrued Interest	2,671,000
Gain on exercise of Primary Warrant	0
Change in fair value of investment	33,922,000
Investment at Fair Value Purchases and Issues	$ 54,202,000