SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Debt and Equity Securities, FV-NI [Line Items]
Cost	$ 156,768		$ 99,859
Gross Unrealized Gain	104,075	$ 264,879
Gross Unrealized Loss	(14,359)	(2,960)
Fair Value	246,484		361,778
Equity securities - Life Sciences Portfolio (Note 3)
Debt and Equity Securities, FV-NI [Line Items]
Cost	48,279		56,037
Gross Unrealized Gain	92,253	262,811
Gross Unrealized Loss	(2,570)	(1,488)
Fair Value	137,962		317,360
Equity securities - other common stock
Debt and Equity Securities, FV-NI [Line Items]
Cost	108,489		43,822
Gross Unrealized Gain	11,822	2,068
Gross Unrealized Loss	(11,789)	$ (1,472)
Fair Value	$ 108,522		$ 44,418

Fair value portion of investments accounted under the equity method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=125513658&loc=d3e32014-111567

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Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117546-209714

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Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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