Fair Value Measurements - Measurement Inputs (Details) - Level 3 $ in Thousands	Dec. 31, 2022 USD ($)
Individually evaluated loans, net of allowance for credit losses
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value	$ 14,732
OREO
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value	$ 1,763
Measurement input, price volatility \| Minimum \| Individually evaluated loans, net of allowance for credit losses
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Debt instrument, measurement input range	0.04
Measurement input, price volatility \| Minimum \| OREO
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
OREO, measurement input range	0.04
Measurement input, price volatility \| Maximum \| Individually evaluated loans, net of allowance for credit losses
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Debt instrument, measurement input range	0.10
Measurement input, price volatility \| Maximum \| OREO
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
OREO, measurement input range	0.10

Impaired loans measured at fair value on nonrecurring basis.

No definition available.

Name:	rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis
Namespace Prefix:	rnst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Value of input used to measure debt instrument, including, but not limited to, convertible and non-convertible debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- 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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Data Type:	xbrli:stringItemType
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- Definition

Value of input used to measure real estate owned by financial institution by financial institution which is not directly related to its business.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Details

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Namespace Prefix:
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- Details

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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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