XML 41 R29.htm IDEA: XBRL DOCUMENT
v3.10.0.1

MANDATORILY REDEEMABLE PREFERRED SECURITIES (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2018
MANDATORILY REDEEMABLE PREFERRED SECURITIES [Abstract] |
Terms of Preferred Securities | The terms of the preferred securities of each trust are as follows:
Trust | Issuance Date | Par Amount |  | Interest Rate | Maturity Date | Call Price
CST III | 7/31/2001 | $24.5 million |  | 3 month LIBOR plus 3.58% (5.94%) | 7/31/2031 | Par
CCT IV | 12/8/2006 | $75.0 million |  | 3 month LIBOR plus 1.65% (3.99%) | 12/15/2036 | Par
MBVT I | 12/15/2004 | $20.6 million |  | 3 month LIBOR plus 1.95% (4.29%) | 12/31/2034 | Par

X
- Definition Tabular disclosure of information pertaining to subordinated long-term debt owed to unconsolidated subsidiary trusts, including but not limited to identification of terms, features, collateral requirements and other information necessary to a fair presentation. + References No definition available. + Details
Name: | cbu_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrustTableTextBlock
Namespace Prefix: | cbu_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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