XML 73 R40.htm IDEA: XBRL DOCUMENT
v3.20.1

Note 1 - Business (Details Textual) | Mar. 31, 2020
--- | ---
Number Of Limited Partnerships In Housing Investments | 10
Percentage of Subsidiaries Common Securities Owned by Parent Company | 100.00%
Southern California1 [Member] |
Number Of Branch Locations | 25
Northern California 1 [Member] |
Number Of Branch Locations | 13
NEW YORK |
Number Of Branch Locations | 10
WASHINGTON |
Number Of Branch Locations | 4
ILLINOIS |
Number Of Branch Locations | 3
TEXAS |
Number Of Branch Locations | 2
NEW JERSEY |
Number Of Branch Locations | 1
HONG KONG |
Number Of Branch Locations | 1

X
- Definition Number of branch locations + References No definition available. + Details
Name: | caty_NumberOfBranchLocations
Namespace Prefix: | caty_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of limited Partnerships in housing investments. + References No definition available. + Details
Name: | caty_NumberOfLimitedPartnershipsInHousingInvestments
Namespace Prefix: | caty_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of subsidiaries common securities owned by parent company. + References No definition available. + Details
Name: | caty_PercentageOfSubsidiariesCommonSecuritiesOwnedByParentCompany
Namespace Prefix: | caty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | srt_StatementGeographicalAxis=caty_SouthernCaliforniaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=caty_NorthernCaliforniaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_NY
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_WA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_IL
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_TX
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_NJ
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_HK
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |