XML 68 R54.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Note 1 - Summary of Significant Accounting Policies (Details Textual) |  | 12 Months Ended
--- | --- | ---
Jan. 01, 2018 USD ($) | Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Number Of Limited Partnerships In Housing Investments |  | 8 |  |
Percentage of Subsidiaries Common Securities Owned by Parent Company |  | 100.00% |  |
Gross Loans Comprised of Commercial Mortgage Loans Percentage |  | 48.00% |  |
Residential Mortgages Properties Percentage |  | 26.40% |  |
Gross Loans Comprised of Commercial Loans Percentage |  | 19.60% |  |
Federal Home Loan Bank Stock |  | $ 17,250,000 | $ 23,085,000 |
Federal Home Loan Bank Stock Shares | shares |  | 172,500 |  |
Minimum Stock Requirement on Outstanding Federal Home Loan Bank Borrowings Shares | shares |  | 150,000 |  |
Maximum Loan Size Portfolio Stratification Homogenous Portfolio |  | $ 500,000 |  |
Variable Interest Entity, Primary Beneficiary, Number of Entities |  | 9 |  |
Equity Securities, FV-NI, Unrealized Gain (Loss), Total |  | $ (2,787,000) |  |
Number of Operating Segments |  | 1 |  |
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings Tax Effect | $ 515,000 |  |  |
Accounting Standards Update 2016-01 [Member] | Retained Earnings [Member] |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption | $ 8,600,000 | $ 8,600,000 |  |
Accounting Standards Update 2016-02 [Member] | Minimum [Member] |  |  |  |
Operating Lease, Liability, Total |  | 32,000,000 |  |
Accounting Standards Update 2016-02 [Member] | Maximum [Member] |  |  |  |
Operating Lease, Liability, Total |  | $ 37,000,000 |  |
California [Member] |  |  |  |
Residential Mortgages Properties Percentage |  | 57.00% |  |

X
- Definition This represents the Federal Home Loan Bank (FHLB) shares owned by the Company as of the balance sheet date. FHLB stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). + References No definition available. + Details
Name: | caty_FederalHomeLoanBankStockShares
Namespace Prefix: | caty_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Commercial loans as a percentage of gross loans. + References No definition available. + Details
Name: | caty_GrossLoansComprisedOfCommercialLoansPercentage
Namespace Prefix: | caty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Commercial mortgage loans as a percentage of gross loans. + References No definition available. + Details
Name: | caty_GrossLoansComprisedOfCommercialMortgageLoansPercentage
Namespace Prefix: | caty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum loan size portfolio stratification, homogenous portfolio. + References No definition available. + Details
Name: | caty_MaximumLoanSizePortfolioStratificationHomogenousPortfolio
Namespace Prefix: | caty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the minimum stock requirement on outstanding federal home loan bank borrowings, in shares. + References No definition available. + Details
Name: | caty_MinimumStockRequirementOnOutstandingFederalHomeLoanBankBorrowingsShares
Namespace Prefix: | caty_
Data Type: | xbrli:sharesItemType
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
- Definition Residential mortgages properties percentage. + References No definition available. + Details
Name: | caty_ResidentialMortgagesPropertiesPercentage
Namespace Prefix: | caty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of increase (decrease) in accumulated other comprehensive income (AOCI) for reclassification to retained earnings of tax effect from remeasurement of deferred tax pursuant to Tax Cuts and Jobs Act. + References No definition available. + Details
Name: | caty_TaxCutsAndJobsActReclassificationFromAOCIToRetainedEarningsTaxEffect
Namespace Prefix: | caty_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of Variable Interest Entities for which the company is the primary beneficiary. + References No definition available. + Details
Name: | caty_VariableInterestEntityPrimaryBeneficiaryNumberOfEntities
Namespace Prefix: | caty_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption. + References No definition available. + Details
Name: | us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84241550&loc=SL75117546-209714 + Details
Name: | us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 325 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809 + Details
Name: | us-gaap_FederalHomeLoanBankStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201601Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_RetainedEarningsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201602Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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