Name:	sfnc_CapitalConservationBuffer
Namespace Prefix:	sfnc_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

Common Equity Tier 1 ratio as defined in the regulations required to be well capitalized.

No definition available.

Name:	sfnc_CommonEquityTier1RatioRequiredToBeWellCapitalized
Namespace Prefix:	sfnc_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

Threshold by which dividends declared exceeds a percentage of net profits in any calendar year.

No definition available.

Name:	sfnc_ThresholdPercentageOfNetProfitsExceededByDividendsDeclaredAnyCalendarYear
Namespace Prefix:	sfnc_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

Threshold by which dividends declared exceeds a percentage of net profits in any calendar year, combined with percentage of retained net profits of the preceding year.

No definition available.

Name:	sfnc_ThresholdPercentageOfNetProfitsExceededByDividendsDeclaredCombinedWithPrecedingYear
Namespace Prefix:	sfnc_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

Ratio of minimum total risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1

Name:	us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

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

Amount of dividends that can be declared or paid without approval of regulatory agency.

No definition available.

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

Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.

Name:	us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

Ratio of minimum Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.