Premises and Equipment, Net - Summary of Premises and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Land	$ 5,124us-gaap_Land	$ 5,124us-gaap_Land
Buildings and improvements	27,372us-gaap_BuildingsAndImprovementsGross	26,897us-gaap_BuildingsAndImprovementsGross
Leasehold improvements	2,487us-gaap_LeaseholdImprovementsGross	2,423us-gaap_LeaseholdImprovementsGross
Furniture and equipment	23,672us-gaap_FurnitureAndFixturesGross	21,743us-gaap_FurnitureAndFixturesGross
Automobiles	451ocfc_AutomobilesAndTrucksGross	281ocfc_AutomobilesAndTrucksGross
Construction in progress	1,667us-gaap_ConstructionInProgressGross	779us-gaap_ConstructionInProgressGross
Total	60,773us-gaap_PropertyPlantAndEquipmentGross	57,247us-gaap_PropertyPlantAndEquipmentGross
Accumulated depreciation and amortization	(36,035)	(33,563)
Premises and equipment, net	$ 24,738us-gaap_PropertyPlantAndEquipmentNet	$ 23,684us-gaap_PropertyPlantAndEquipmentNet

Automobiles And Trucks, Gross

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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