XML 23 R48.htm IDEA: XBRL DOCUMENT v2.4.1.9
Securities (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Realized gains and losses      
Gross realized gains $ 3,392,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGains $ 2,602,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGains  
Gross realized losses (16,000)us-gaap_AvailableforsaleSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments (480,000)us-gaap_AvailableforsaleSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments  
Net realized gains 3,376,000us-gaap_AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments 2,122,000us-gaap_AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments  
Securities available-for-sale:      
Amortized Cost 5,201,001,000us-gaap_AvailableForSaleSecuritiesAmortizedCost   5,894,509,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
Gross Unrealized Gains 33,649,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax   32,788,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Gross Unrealized Losses (24,262,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax   (44,314,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Fair Value 5,210,388,000us-gaap_AvailableForSaleSecurities   5,882,983,000us-gaap_AvailableForSaleSecurities
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 3,413,806,000us-gaap_HeldToMaturitySecurities   3,427,031,000us-gaap_HeldToMaturitySecurities
Gross Unrealized Gains 101,945,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain   72,659,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Gross Unrealized Losses (5,198,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss   (15,043,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Fair Value 3,510,553,000us-gaap_HeldToMaturitySecuritiesFairValue   3,484,647,000us-gaap_HeldToMaturitySecuritiesFairValue
Sales of securities available-for-sale 398,166,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities 377,115,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities  
Sales of securities held-to-maturity 0us-gaap_ProceedsFromSaleOfHeldToMaturitySecurities 0us-gaap_ProceedsFromSaleOfHeldToMaturitySecurities  
Interest and dividend income on securities (including trading securities)      
Taxable interest income 35,000,000us-gaap_InterestIncomeSecuritiesTaxable 36,000,000us-gaap_InterestIncomeSecuritiesTaxable  
Nontaxable interest income 7,000,000cyn_InterestIncomeSecuritiesFederalTaxExempt 5,500,000cyn_InterestIncomeSecuritiesFederalTaxExempt  
Dividend income 11,000us-gaap_DividendIncomeOperating 9,000us-gaap_DividendIncomeOperating  
Total securities 8,730,000,000us-gaap_MarketableSecurities   9,480,000,000us-gaap_MarketableSecurities
Total debt securities      
Securities available-for-sale:      
Amortized Cost 5,199,660,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember		   5,893,001,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember
Gross Unrealized Gains 33,430,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember		   30,800,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember
Gross Unrealized Losses (23,852,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember		   (43,964,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember
Fair Value 5,209,238,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember		   5,879,837,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 3,413,806,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_DebtSecuritiesMember		    
U.S. Treasury      
Securities available-for-sale:      
Amortized Cost 115,893,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember		   116,919,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember
Gross Unrealized Gains 29,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember		   17,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember
Gross Unrealized Losses (15,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember		   (10,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember
Fair Value 115,907,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember		   116,926,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_USTreasurySecuritiesMember
Federal agency - Debt      
Securities available-for-sale:      
Amortized Cost 1,219,481,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   1,401,303,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Gross Unrealized Gains 1,168,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   558,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Gross Unrealized Losses (429,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   (3,280,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Fair Value 1,220,220,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   1,398,581,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 286,581,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   292,932,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Gross Unrealized Gains 9,923,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   6,430,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Gross Unrealized Losses (72,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   (255,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Fair Value 296,432,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember		   299,107,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Federal agency - MBS      
Securities available-for-sale:      
Amortized Cost 99,891,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   102,939,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Gross Unrealized Gains 2,498,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   2,601,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Gross Unrealized Losses (874,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   (1,014,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value 101,515,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   104,526,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 556,931,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   553,589,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Gross Unrealized Gains 20,346,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   13,427,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Gross Unrealized Losses (567,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   (2,275,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value 576,710,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		   564,741,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
CMOs - Federal agency      
Securities available-for-sale:      
Amortized Cost 3,204,823,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   3,599,831,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Gross Unrealized Gains 22,016,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   19,628,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Gross Unrealized Losses (21,953,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   (38,869,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Fair Value 3,204,886,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   3,580,590,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 1,766,325,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   1,811,574,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Gross Unrealized Gains 48,270,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   29,998,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Gross Unrealized Losses (2,749,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   (10,292,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
Fair Value 1,811,846,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember		   1,831,280,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= cyn_FederalAgencyCollateralizedMortgageObligationsMember
CMOs - Non-agency      
Securities available-for-sale:      
Amortized Cost 23,147,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember		   24,385,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember
Gross Unrealized Gains 24,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember		   40,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember
Gross Unrealized Losses (360,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember		   (411,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember
Fair Value 22,811,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember		   24,014,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= cyn_NonAgencyCollateralizedMortgageObligationsMember
State and municipal      
Securities available-for-sale:      
Amortized Cost 421,419,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   473,272,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Gross Unrealized Gains 6,257,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   6,139,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Gross Unrealized Losses (218,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   (380,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Fair Value 427,458,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   479,031,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 717,937,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   682,705,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Gross Unrealized Gains 23,084,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   22,732,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Gross Unrealized Losses (1,810,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   (1,997,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Fair Value 739,211,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		   703,440,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Other debt securities      
Securities available-for-sale:      
Amortized Cost 115,006,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		   174,352,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Gross Unrealized Gains 1,438,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		   1,817,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Gross Unrealized Losses (3,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		    
Fair Value 116,441,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		   176,169,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Securities held-to-maturity:      
Held-to-maturity Securities, Amortized Cost 86,032,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		   86,231,000us-gaap_HeldToMaturitySecurities
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Gross Unrealized Gains 322,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		   72,000us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Gross Unrealized Losses     (224,000)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Fair Value 86,354,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember		   86,079,000us-gaap_HeldToMaturitySecuritiesFairValue
/ invest_InvestmentAxis
= us-gaap_OtherDebtSecuritiesMember
Equity securities and mutual funds      
Securities available-for-sale:      
Amortized Cost 1,341,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember		   1,508,000us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember
Gross Unrealized Gains 219,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember		   1,988,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember
Gross Unrealized Losses (410,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember		   (350,000)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember
Fair Value $ 1,150,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember		   $ 3,146,000us-gaap_AvailableForSaleSecurities
/ invest_InvestmentAxis
= cyn_EquitySecuritiesAndMutualFundsMember