XML 59 R47.htm IDEA: XBRL DOCUMENT
v3.19.2

ACQUISITIONS - Pro Forma Information (Details) - SI Financial Group, Inc. - USD ($) $ in Thousands | 6 Months Ended
--- | ---
Jun. 30, 2019 | Jun. 30, 2018
Business Acquisition [Line Items] |  |
Net interest income | $ 195,624 | $ 202,709
Non-interest income | 43,732 | 44,228
Income available to common shareholders | $ 60,357 | $ 67,666

X
- Definition Business Acquisition, Pro Forma Interest Income (Expense), Net + References No definition available. + Details
Name: | bhlb_BusinessAcquisitionProFormaInterestIncomeExpenseNet
Namespace Prefix: | bhlb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Business Acquisition, Pro Forma Net Income (Loss) Available To Common Stockholders, Basic + References No definition available. + Details
Name: | bhlb_BusinessAcquisitionProFormaNetIncomeLossAvailableToCommonStockholdersBasic
Namespace Prefix: | bhlb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Business Acquisition, Pro Forma Noninterest Income + References No definition available. + Details
Name: | bhlb_BusinessAcquisitionProFormaNoninterestIncome
Namespace Prefix: | bhlb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=bhlb_SIFinancialGroupInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |