INVESTMENT SECURITIES (Detail Textuals 1) $ in Thousands	Sep. 30, 2015 USD ($) Security	Dec. 31, 2014 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on investment in/of certain of the corporation's corporate securities	$ 628	$ 1,132
Corporate Securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on investment in/of certain of the corporation's corporate securities	$ 332	316
Pooled Trust Preferred Issues
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss position \| Security	2
Percentage of book value of corporation's investment portfolio	1.21%
Percentage of market value of corporation's investment portfolio	0.96%
Pooled Trust Preferred Issues \| ALESCO 9A \| Moody's, Baa3 Rating \| Corporate Securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on investment in/of certain of the corporation's corporate securities	$ 309	313
Pooled Trust Preferred Issues \| PRETSL XXVII \| Moody's, A2 Rating \| Corporate Securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on investment in/of certain of the corporation's corporate securities	$ 15	$ 1

Represents the percentage of book value of Corporation's investment portfolio.

No definition available.

Name:	rivr_PercentageOfBookValueOfCorporationsInvestmentPortfolio
Namespace Prefix:	rivr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of market value of Corporation's investment portfolio.

+ References

No definition available.

+ Details

Name:	rivr_PercentageOfMarketValueOfCorporationsInvestmentPortfolio
Namespace Prefix:	rivr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

+ Details

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

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
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

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

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTermsAxis=us-gaap_TrustPreferredSecuritiesSubjectToMandatoryRedemptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentSecondaryCategorizationAxis=rivr_AlescoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditRatingMoodysAxis=us-gaap_MoodysBaa3RatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentSecondaryCategorizationAxis=rivr_PretslMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditRatingMoodysAxis=us-gaap_MoodysA2RatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: