INVESTMENTS - Apollo's Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments, at fair value	$ 1,884,388	$ 1,053,556
Equity method investments	964,521	1,048,732
Performance allocations	1,128,160	1,507,571
Total Investments	$ 3,977,069	$ 3,609,859

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 5D
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
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