INCOME TAXES - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory rate		21.00%	21.00%	21.00%
State income taxes, net of federal benefit		1.30%	1.90%	1.80%
Non-U.S. income tax rate differential		3.50%	1.30%	5.30%
Effect of tax law changes		0.00%	(0.50%)	(0.60%)
Nondeductible FDIC premiums		1.30%	0.40%	0.70%
Basis difference in affiliates		(0.10%)	(0.10%)	(2.40%)
Tax advantaged investments		(4.40%)	(2.30%)	(2.00%)
Valuation allowance releases		(4.40%)	(3.00%)	0.00%
Other, net		0.30%	(0.20%)	(1.00%)
Effective income tax rate		18.50%	18.50%	22.80%
Tax Reform benefit	$ 94			$ 94

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Subparagraph (SAB Topic 6.I.Fact.4)
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to equity in earnings (loss) of unconsolidated subsidiaries exempt from income taxes.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Amount of income tax expense (benefit) from effect of Tax Cuts and Jobs Act.

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