Cash and due from banks (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Cash and Due from Banks [Abstract]
Federal reserve bank mandated reserve amount	$ 24.8	$ 21.9

The mandated reserve amounts required of federal reserve bank.

No definition available.

Name:	cacb_FederalReserveBankMandatedReserveAmount
Namespace Prefix:	cacb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant