Financial impact on date of restructure.

No definition available.

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Namespace Prefix:	sfnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

+ Details

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Period Type:	duration

- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

+ Details

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

- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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- Details

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- Details

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- Details

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- Details

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- Details

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Loans and Allowance for Credit Losses - Loans Restructured as TDRs, Excluding Loans Acquired, Segregated by Class of Loans (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 USD ($) loan	Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| loan	1	1	1	1
Balance Prior to TDR	$ 784	$ 147	$ 784	$ 147
Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| loan	1	1	1	1
Balance Prior to TDR	$ 784	$ 147	$ 784	$ 147
Balance	778	147	778	147
Financial Impact on Date of Restructure	0	0	0	0
Real Estate \| Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	0	147	0	147
Real Estate \| Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 778	$ 0	$ 778	$ 0
Real Estate \| Other commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| loan	1		1
Balance Prior to TDR	$ 784		$ 784
Balance	778		778
Financial Impact on Date of Restructure	0		0
Real Estate \| Other commercial \| Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	0		0
Real Estate \| Other commercial \| Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 778		$ 778
Real Estate \| Single family residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| loan		1		1
Balance Prior to TDR		$ 147		$ 147
Balance		147		147
Financial Impact on Date of Restructure		0		0
Real Estate \| Single family residential \| Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		147		147
Real Estate \| Single family residential \| Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		$ 0		$ 0