Consumer and other retail loans charged off past due period.

No definition available.

Name:	rnst_ConsumerAndOtherRetailLoansChargedOffPastDuePeriod
Namespace Prefix:	rnst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of loans contractual interest cash flows.

+ References

No definition available.

+ Details

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

- Definition

Fair value of loans contractual principal cash flows amount.

+ References

No definition available.

+ Details

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

- Definition

Fair value of loans contractual purchase discount.

+ References

No definition available.

+ Details

Name:	rnst_FairValueOfLoansContractualPurchaseDiscount
Namespace Prefix:	rnst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair value of loans future interest payments.

+ References

No definition available.

+ Details

Name:	rnst_FairValueOfLoansFutureInterestPayments
Namespace Prefix:	rnst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Interest income recognized.

+ References

No definition available.

+ Details

Name:	rnst_InterestIncomeRecognized
Namespace Prefix:	rnst_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loan grades range.

+ References

No definition available.

+ Details

Name:	rnst_LoanGradesRange
Namespace Prefix:	rnst_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	rnst_LoansAndAllowanceForLoanLossesAdditionalTextualAbstract
Namespace Prefix:	rnst_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Mortgage and commercial loans discontinued past due period.

+ References

No definition available.

+ Details

Name:	rnst_MortgageAndCommercialLoansDiscontinuedPastDuePeriod
Namespace Prefix:	rnst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Nonperforming loans charged off past due period.

+ References

No definition available.

+ Details

Name:	rnst_NonperformingLoansChargedOffPastDuePeriod
Namespace Prefix:	rnst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum duration past due for restructured loans to be considered performing.

+ References

No definition available.

+ Details

Name:	rnst_RestructuredLoansDiscontinuedPastDuePeriod
Namespace Prefix:	rnst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Restructured loans equal to greater than ninety days past due.

+ References

No definition available.

+ Details

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

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

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

- Definition

Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18794-111554

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph a

-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(a))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LoansReceivableNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Loans and the Allowance for Loan Losses (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Mortgage and commercial loans discontinued past due period			90 days
Consumer and other retail loans charged-off past due period			120 days
Restructured loans discontinued past due period			90 days		90 days
Restructured loans	$ 0		$ 0		$ 646
Interest income recognized using the cash-basis method of income recognition	0	814	0	1,128
Nonperforming loans charged-off past due period			90 days
Allowance for loan losses attributable to restructured loans	46,250		46,250		44,347
Remaining availability under commitments to lend additional funds on restructured loans	93		93		288
Fair value of loans contractual principal cash flows amount	641,495		641,495
Fair value of loans contractual interest cash flows	12,292		12,292
Fair value of loans contractual interest payments			3,355
Fair value of loans contractual purchase discount			36,395
Watch [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			5
Maximum [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			9
Maximum [Member] \| Pass [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			4
Maximum [Member] \| Substandard [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			9
Minimum [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			1
Minimum [Member] \| Pass [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			1
Minimum [Member] \| Substandard [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade)			6
Restructured Loans [Member]
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Outstanding balance of restructured loans	12,662		12,662		11,420
Allowance for loan losses attributable to restructured loans	$ 3,218		$ 3,218		$ 3,969