Employee Benefits (Detail Textuals 1) (USD $)	1 Months Ended	12 Months Ended
Oct. 31, 2009	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2008
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Percentage of W-2 earnings for employees hired prior to September 1, 2005 and for employees hired on or after September 1, 2005		6.00%
Match rate as percentage of first 6% of W-2 earnings for employees hired prior to September 1, 2005				50.00%
Match rate as percentage of first 6% of W-2 earnings for employees hired on or after September 1, 2005				100.00%
Changed match rate for employees hired on or after September 1, 2005	50.00%	75.00%
Bank's expense for the plan		$ 65,000	$ 45,000

Represents the changed match rate for employees hired on or after specified period.

No definition available.

Name:	rivr_DefinedContributionPlanChangedMatchRateForEmployeeHiredOnOrAfter1September2005
Namespace Prefix:	rivr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the match rate as percentage of first 6% of W-2 earnings for employees hired on or after specified period.

No definition available.

Name:	rivr_DefinedContributionPlanMatchRateAsPercentageOfFirstSixPercentOfW2EarningsForEmployeesHiredOnOrAfter1September2005
Namespace Prefix:	rivr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the match rate as percentage of first 6% of W-2 earnings for employees hired prior to specified period.

No definition available.

Name:	rivr_DefinedContributionPlanMatchRateAsPercentageOfFirstSixPercentOfW2EarningsForEmployeesHiredPriorTo1September2005
Namespace Prefix:	rivr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of the W-2 earnings for employees as specified in the retirement savings 401(k) plan.

No definition available.

Name:	rivr_DefinedContributionPlanPercentageOfW2EarningsForSpecifiedEmployees
Namespace Prefix:	rivr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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

Amount of administrative expenses incurred by a defined contribution plan.

No definition available.

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