Consumer and other retail loans charged off past due period.

No definition available.

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- Definition

Fair value of loans contractual interest cash flows.

+ References

No definition available.

+ Details

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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

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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

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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

Loan grades range.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Loans and the allowance for loan losses.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

Mortgage and commercial loans discontinued past due period.

+ References

No definition available.

+ Details

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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

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Restructured Loans

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
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- 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 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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-Section 50
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Reference 3: 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 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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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

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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 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

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

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Period Type:

- Details

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Period Type:

- Details

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- Details

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Loans and the Allowance for Loan Losses - (Details Textual) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) loan_grade loan	Sep. 30, 2015 USD ($) loan	Dec. 31, 2015 USD ($)
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Mortgage and commercial loans discontinued past due period (in days)	90 days
Consumer and other retail loans charged-off past due period (in days)	120 days
Nonperforming loans charged-off past due period (in days)	90 days
Number of restructured loans \| loan	0	1
Restructured loans discontinued past due period (in days)	90 days	90 days
Allowance for loan losses attributable to restructured loans	$ 45,924		$ 42,437
Remaining availability under commitments to lend additional funds on restructured loans	11		$ 11
Fair value of loans contractual principal cash flows amount	82,248
Fair value of loans contractual interest cash flows	35
Fair value of loans contractual interest payments	1,862
Fair value of loans contractual purchase discount	$ 39,179
Watch
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	5
Maximum
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	9
Maximum \| Pass
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	4
Maximum \| Substandard
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	9
Minimum
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	1
Minimum \| Pass
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	1
Minimum \| Substandard
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Loan grades range (loan grade) \| loan_grade	6
Nonaccruing Loans
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Outstanding balance of restructured loans		$ 35
Restructured Loans
Loans and Allowance for Loan Losses (Additional Textual) [Abstract]
Outstanding balance of restructured loans	$ 9,764	13,956
Allowance for loan losses attributable to restructured loans	$ 321	$ 1,343