Investment Securities (Detail Textuals 1) (USD $)	6 Months Ended	12 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on debt investments	$ (3,748,000)	$ (587,000)
Pooled Trust Preferred Issues
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss position	2	2
Below investment grade rated investments as percentage of book value of corporations investments	1.30%
Below investment grade rated investments as percentage of market value of corporations investments	1.00%
Pooled Trust Preferred Issues \| ALESCO 9A \| Moody's, Ba2 Rating
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on debt investments	395,000	465,000
Pooled Trust Preferred Issues \| PRETSL XXVII \| Moody's, A2 Rating
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses on debt investments	$ 48,000	$ 56,000

Represents the percentage of aggregate book value of investments for investment securities.

No definition available.

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

- Definition

Represents the percentage of aggregate market value of investments for investment securities.

+ References

No definition available.

+ Details

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

- Definition

Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

+ 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_AvailableForSaleSecuritiesGrossUnrealizedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

- Details

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