Loans Receivable, Net - Recorded Investment in Residential and Consumer Loans Based on Payment Activity Excluding PCI Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Non-performing	$ 15,330	$ 18,274
Total loans	3,146,729	1,997,938
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-performing	7,102	5,779
Total loans	1,136,697	842,006
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-performing	1,226	1,576
Total loans	259,416	193,160
Residential Real Estate [Member] \| Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	1,129,595	836,227
Non-performing	7,102	5,779
Total loans	1,136,697	842,006
Residential Real Estate [Member] \| Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	258,190	191,584
Non-performing	1,226	1,576
Total loans	$ 259,416	$ 193,160

Credit quality of loan receivables performing.

No definition available.

Name:	ocfc_CreditQualityOfLoanReceivablesPerforming
Namespace Prefix:	ocfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5111-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedNonperformingNonaccrualOfInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: