LOANS AND ALLOWANCE - Activity in allowance for loan losses (Details 1) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:			$ 4,005
Provision for losses	$ 99	$ 24	198	$ 198
Balances at end of period	3,675		3,675
Loans Receivable
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	3,654	4,196	4,005	4,510
Provision for losses	99	24	198	198
Loans charged off	(127)	(744)	(729)	(1,277)
Recoveries on loans	49	286	201	331
Balances at end of period	3,675	3,762	3,675	3,762
Loans Receivable \| Construction/Land
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	906	694	740	$ 676
Provision for losses	$ 16	$ (18)	115
Loans charged off
Recoveries on loans			67
Balances at end of period	$ 922	$ 676	922	$ 676
Loans Receivable \| 1-4 Family
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	1,423	1,524	1,977	1,749
Provision for losses	45	(33)	60	223
Loans charged off	(83)	(137)	(654)	(621)
Recoveries on loans	2	37	4	40
Balances at end of period	1,387	1,391	1,387	1,391
Loans Receivable \| Multi-Family
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	23	414	28	404
Provision for losses	$ (16)	400	(20)	410
Loans charged off		$ (511)		$ (511)
Recoveries on loans	$ 20		19
Balances at end of period	27	$ 303	27	$ 303
Loans Receivable \| Nonresidential
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	1,160	1,378	1,107	1,470
Provision for losses	$ 60	(311)	42	(404)
Loans charged off		(61)		(72)
Recoveries on loans	$ 20	226	91	238
Balances at end of period	1,240	1,232	1,240	1,232
Loans Receivable \| Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	141	176	151	189
Provision for losses	(39)	$ (31)	(46)	$ (51)
Loans charged off	$ (15)		(18)
Recoveries on loans		$ 7		$ 14
Balances at end of period	$ 87	152	87	152
Loans Receivable \| Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Balances at beginning of period:	1	10	2	22
Provision for losses	33	17	47	20
Loans charged off	(29)	(35)	(57)	(73)
Recoveries on loans	7	16	20	39
Balances at end of period	$ 12	$ 8	$ 12	$ 8

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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=49124121&loc=SL6953423-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

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

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

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

Reference 5: 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

Amount of expense related to estimated loss from loan and lease transactions.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.11)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

+ Details

Name:	us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_LoansReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rivr_ConstructionAndLandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rivr_OneToFourFamilyResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rivr_MultiFamilyResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rivr_NonresidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: