SUMMARY OF CRITICAL ACCOUNTING POLICIES AND ESTIMATES - Narrative (Details)	3 Months Ended
Mar. 31, 2021 USD ($)
New Accounting Pronouncements or Change in Accounting Principle
Asset impairment	$ 0
Common Class B and Class A
New Accounting Pronouncements or Change in Accounting Principle
Annual return (as a percent)	22.50%
Percentage of aggregate capital investment to be added to original per-unit price to determine cash purchase price (as a percent)	50.00%

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration