Name:	sfnc_BusinessCombinationConversionOfEachOutstandingCommonStockToCash
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Represents information about conversion of each outstanding common stock of the merger to company's common stock in a business combination transaction.

No definition available.

Name:	sfnc_BusinessCombinationConversionOfEachOutstandingCommonStockToCompanysCommonStock
Namespace Prefix:	sfnc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The amount of deposit recognized as of the acquisition date.

No definition available.

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Data Type:	xbrli:monetaryItemType
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The amount of loans recognized as of the acquisition date.

No definition available.

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Namespace Prefix:	sfnc_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Number of shares of equity interests issued or issuable to acquire entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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Amount of assets acquired at the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of liabilities assumed at the acquisition date.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Data Type:	num:percentItemType
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Maximum amount borrowed under the credit facility at any time during the period.

No definition available.

Name:	us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

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

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Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_BusinessAcquisitionAxis=sfnc_OKSBMergerMember
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