XML 116 R101.htm IDEA: XBRL DOCUMENT
v3.19.1

Deposits - Interest Expense on Deposits (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Deposits [Abstract] |  |  |
Interest-bearing demand accounts | $ 8 | $ 21 | $ 67
Money market accounts | 855 | 472 | 418
Savings accounts | 744 | 520 | 489
Certificates of deposit $250,000 and greater | 472 | 480 | 614
Certificates of deposit less than $250,000 | 228 | 214 | 282
Total deposits | $ 2,307 | $ 1,707 | $ 1,870

X
- Definition Interest Expense, Time Deposits, $250,000 or More + References No definition available. + Details
Name: | nrim_InterestExpenseTimeDeposits250000orMore
Namespace Prefix: | nrim_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest Expense, Time Deposits, Less than $250,000 + References No definition available. + Details
Name: | nrim_InterestExpenseTimeDepositsLessthan250000
Namespace Prefix: | nrim_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DepositsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate amount of interest expense on all deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpenseDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest expense on domestic notice of withdrawal demand deposit liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpenseDomesticDepositLiabilitiesNoticeOfWithdrawal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest expense incurred on all money market deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpenseMoneyMarketDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest expense incurred on all savings account deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpenseSavingsDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration