Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 835
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-Section 55
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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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BORROWINGS (SHUSA) (Narrative) (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Short-term debt borrowings due February 2021
Debt Instrument [Line Items]
Debt issued	$ 125,000,000.0
Stated interest rate	2.00%
Short-term borrowings	$ 125,000,000	$ 0
Senior Notes
Debt Instrument [Line Items]
Debt issued	2,100,000,000
Senior Notes \| 5.83% senior notes, due March 2023
Debt Instrument [Line Items]
Debt issued	$ 500,000,000.0
Stated interest rate	5.83%
Senior Notes \| Senior floating rate note due April 2023
Debt Instrument [Line Items]
Debt issued	$ 447,100,000
Senior Notes \| 3.45% senior fixed rate note due June 2025
Debt Instrument [Line Items]
Debt issued	$ 1,000,000,000.0
Stated interest rate	3.45%
Senior Notes \| 2.65% senior notes due April 2020
Debt Instrument [Line Items]
Stated interest rate	2.65%
Debt repurchased	$ 1,000,000,000.0
Senior Notes \| 3.50% senior notes due June 2024
Debt Instrument [Line Items]
Debt issued			$ 1,000,000,000.0
Stated interest rate	3.50%		3.50%
Senior Notes \| 2.70% senior notes due May 2019
Debt Instrument [Line Items]
Stated interest rate			2.70%
Debt repurchased			$ 178,700,000