FAIR VALUE MEASUREMENTS - UNREALIZED GAIN (LOSS) ON INVESTMENTS (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Net unrealized gains included in earnings related to investments held at end of period	$ 4.0
Net unrealized losses included in earnings related to investments held at end of period		$ 14.2

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

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=120269885&loc=SL75117546-209714

Name:	us-gaap_EquitySecuritiesFvNiUnrealizedGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration