LONG-TERM DEBT, NET - If-Converted Value in Excess of Principal (Details) - Senior Notes - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2021	Dec. 31, 2020
2022 Exchangeable Notes
Debt Instrument [Line Items]
If-converted value in excess of principal	$ 1,329.4	$ 1,261.2
2026 Exchangeable Notes
Debt Instrument [Line Items]
If-converted value in excess of principal	456.4	418.3
2030 Exchangeable Notes
Debt Instrument [Line Items]
If-converted value in excess of principal	$ 496.8	$ 457.2

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031898-161870

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