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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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration, liability	$ 2,739	$ 2,879
Level 3 \| Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-marketable equity securities		11,800
Biomatrica, Inc
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration, liability	20,000
Epic Sciences
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment owned, at fair value	$ 10,800	$ 10,800	$ 10,800