INVESTMENTS - Pledged Investments (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Cash and investments at fair value on deposit with, or in trust accounts for the benefit of various counterparties	$ 7.1	$ 7.9
Cash and investments at fair value on deposit with, or in trust accounts for the benefit of U.S. state regulatory authorities	$ 1.1	$ 1.2

The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Name:	us-gaap_AssetsHeldInTrust
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant