One-time fee for a royalty-free, fully-paid, perpetual and assignable license to patents.

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Represents potential future payments still contingent upon achievement of milestones under a collaborative arrangement.

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Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Balance held at close of period in number of shares.

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LICENSE AND COLLABORATION AGREEMENTS - Biocartis (Details) - Biocartis N.V € in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2020 EUR (€)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2017 USD ($) shares	Sep. 30, 2017 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Investment owned (in shares) \| shares				270,000
Investment owned, at fair value \| $		$ 1.4	$ 1.7	$ 4.0
Sales Milestone Range One
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments contingent on milestones \| €	€ 2.5
Expansion Of Collaboration To Oncology
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments contingent on milestones \| €	€ 2.0
Licensing Agreements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
One time fee for license to patents \| $					$ 3.2