Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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- Definition

Derivatives, Value Shortfalls Threshold Triggering Additional Collateral Requirements

+ References

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- Definition

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+ References

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- Definition

Those fees and commissions generated from corporate and retail banking related operations of the Broker Dealer.

+ References

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959

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Derivatives - Additional Information (Details) (USD $)	12 Months Ended
Derivatives - Additional Information (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Value Shortfalls Threshold Triggering Additional Collateral Requirements	$ 250,000
Derivative, Notional Amount	23,600,000invest_DerivativeNotionalAmount	25,800,000invest_DerivativeNotionalAmount
Banking Fees and Commissions	0us-gaap_BankingFeesAndCommissions	180,000us-gaap_BankingFeesAndCommissions	0us-gaap_BankingFeesAndCommissions
Unfunded Lending Commitment	39,600,000nrim_UnfundedLendingCommitment	0nrim_UnfundedLendingCommitment
Variable to Fixed
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,800,000
Derivative, Number of Instruments Held	2
Fixed to Variable
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,800,000
Derivative, Number of Instruments Held	2
RML
Derivatives, Fair Value [Line Items]
Unfunded Lending Commitment	$ 39,600,000