XML 92 R77.htm IDEA: XBRL DOCUMENT
v3.8.0.1

LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES (Details) $ in Millions | Dec. 31, 2017 USD ($)
--- | ---
LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES [Abstract] |
Undivided profits legally available for the payments of dividends | $ 69.0
Percentage of Bank's capital and surplus that can be transferred to Company, maximum | 10.00%
Aggregate percentage of Bank's capital and surplus that can be transferred to Company, maximum | 20.00%

X
- Definition The aggregate maximum percentage of the Bank's capital and surplus that can be transferred to Company. + References No definition available. + Details
Name: | cbu_AggregateBankCapitalAndSurplusTransferableToCompanyMaximum
Namespace Prefix: | cbu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum percentage of the Bank's capital and surplus that can be transferred to Company. + References No definition available. + Details
Name: | cbu_BankCapitalAndSurplusTransferableToCompanyMaximum
Namespace Prefix: | cbu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Amount of dividends available for payment after computation of statutory restrictions on capital surplus. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(e)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPayments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant