XML 95 R122.htm IDEA: XBRL DOCUMENT
v3.20.1

Quarterly Financial Data (Unaudited) (Details Narrative) | May 31, 2018
--- | ---
Quarterly Financial Information Disclosure [Abstract] |
Stock dividend paid | 5.00%

X
- Definition The stock dividend paid, represented as a percentage. + References No definition available. + Details
Name: | cofs_StockDividendPaid
Namespace Prefix: | cofs_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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