Derivative Instruments and Hedging Activities - Summary of Offsetting of Financial Liabilities and Derivative Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	$ 13,698	$ 10,074
Interest Rate Swaps
Offsetting Liabilities [Line Items]
Gross Amount of Recognized Liabilities	1,639	5,058
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	1,639	5,058
Gross amounts not offset in the consolidated balance sheet, Financial instruments	0	0
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	2	4,872
Gross amounts not offset in the consolidated balance sheet, Net amount	$ 1,637	$ 186

Derivative Asset Fair Value Of Asset Derivative Not Offset

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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 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 liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Fair value, after effects of master netting arrangements, 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 liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of asset associated with 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.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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