Derivatives - Enforceable Master Netting Arrangement (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Derivative [Line Items]
Gross Amounts of Recognized Assets	$ 17,802	$ 6,400
Gross Amounts Offset in the Balance Sheet, Assets	(17,441)	(6,205)
Fair Value, Assets	361	195
Financial Instruments, Assets
Cash Collateral Received, Assets
Fair Value, Assets	361	195
Gross Amounts of Recognized Liabilities	17,802	6,400
Gross Amounts Offset in the Balance Sheet, Liabilities	(17,441)	(6,205)
Fair Value, Liabilities	361	195
Financial Instruments, Liabilities
Cash Collateral Received, Liabilities
Fair Value, Liabilities	361	195
Customer Interest Rate Swaps [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets	17,802
Gross Amounts Offset in the Balance Sheet, Assets	(17,441)
Fair Value, Assets	361
Financial Instruments, Assets
Cash Collateral Received, Assets
Fair Value, Assets	361
Gross Amounts of Recognized Liabilities		6,400
Gross Amounts Offset in the Balance Sheet, Liabilities		(6,205)
Fair Value, Liabilities		195
Financial Instruments, Liabilities
Cash Collateral Received, Liabilities
Fair Value, Liabilities		195
3rd Party Interest Rate Swaps [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets		6,400
Gross Amounts Offset in the Balance Sheet, Assets		(6,205)
Fair Value, Assets		195
Financial Instruments, Assets
Cash Collateral Received, Assets
Fair Value, Assets		195
Gross Amounts of Recognized Liabilities	17,802
Gross Amounts Offset in the Balance Sheet, Liabilities	(17,441)
Fair Value, Liabilities	361
Financial Instruments, Liabilities
Cash Collateral Received, Liabilities
Fair Value, Liabilities	$ 361

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset against an obligation to return collateral under a master netting arrangement.

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Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against an obligation to return collateral. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset against a right to receive collateral under a master netting arrangement.

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Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against the right to receive collateral. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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The carrying amount of liabilities as of the balance sheet date that pertain to principal and customer trading transactions, or which may be incurred with the objective of generating a profit from short-term fluctuations in price as part of an entity's market-making, hedging and proprietary trading. Examples include short positions in securities, derivatives and commodities, obligations under repurchase agreements, and securities borrowed arrangements.

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No definition available.

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