XML 27 R77.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Measurements Asset and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Investment securities available for sale:    
Investment securities available for sale, at fair value $ 5,358,310us-gaap_AvailableForSaleSecurities $ 5,396,812us-gaap_AvailableForSaleSecurities
Trading assets 42,336us-gaap_DerivativeAssets 35,163us-gaap_DerivativeAssets
Liabilities, Fair Value Disclosure [Abstract]    
Trading liabilities 44,730us-gaap_DerivativeLiabilities 37,329us-gaap_DerivativeLiabilities
Fair Value, Measurements, Recurring [Member]    
Investment securities available for sale:    
Trading assets 52,132us-gaap_DerivativeAssets
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= us-gaap_FairValueMeasurementsRecurringMember
Liabilities, Fair Value Disclosure [Abstract]    
Trading liabilities 52,636us-gaap_DerivativeLiabilities
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= us-gaap_FairValueMeasurementsRecurringMember		 45,818us-gaap_DerivativeLiabilities
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= us-gaap_FairValueMeasurementsRecurringMember
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 1,002us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Obligations of state and political subdivisions (municipal securities) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 524,587us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Government-Sponsored Enterprise (GSE) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 3,675,114us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Private Label [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 1,953us-gaap_AvailableForSaleSecurities
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= us-gaap_FairValueMeasurementsRecurringMember
Fair Value, Measurements, Recurring [Member] | GSE commercial mortgage-related securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 1,149,256us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Other Debt And Other Equity Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 6,398us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 4,200us-gaap_AvailableForSaleSecurities
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Trading assets 0us-gaap_DerivativeAssets
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Liabilities, Fair Value Disclosure [Abstract]    
Trading liabilities 0us-gaap_DerivativeLiabilities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 1,002us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Obligations of state and political subdivisions (municipal securities) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Government-Sponsored Enterprise (GSE) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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= us-gaap_FairValueMeasurementsRecurringMember
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Private Label [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | GSE commercial mortgage-related securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Debt And Other Equity Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 3,198us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 5,353,910us-gaap_AvailableForSaleSecurities
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Trading assets 48,447us-gaap_DerivativeAssets
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Liabilities, Fair Value Disclosure [Abstract]    
Trading liabilities 50,841us-gaap_DerivativeLiabilities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Obligations of state and political subdivisions (municipal securities) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 524,587us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Government-Sponsored Enterprise (GSE) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 3,675,114us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Private Label [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 1,953us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | GSE commercial mortgage-related securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 1,149,256us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Debt And Other Equity Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 3,000us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 200us-gaap_AvailableForSaleSecurities
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Liabilities, Fair Value Disclosure [Abstract]    
Trading liabilities 1,795us-gaap_DerivativeLiabilities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Obligations of state and political subdivisions (municipal securities) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Government-Sponsored Enterprise (GSE) [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Private Label [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | GSE commercial mortgage-related securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value 0us-gaap_AvailableForSaleSecurities
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/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Debt And Other Equity Securities [Member]    
Investment securities available for sale:    
Investment securities available for sale, at fair value $ 200us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= asb_OtherDebtAndOtherEquitySecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 $ 200us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= asb_OtherDebtAndOtherEquitySecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember